Although I fear another mindless trance/techno vulgarization of the originals, I'll give it a shot.

Track 1: e1m1 is awesome. Very metal. 5/5
Track 2: e1m4 is rythmic trance crap and I dislike it. 2/5
Track 3: e1m2 is creepy synthesizer and I like it. 3/5

More to come.

Track 4: (e2m9) is fairly heavy on bass, but not THUD THUD type bass. Otherwise good. 4/5
Track 5: (e2m8) sporking rocks. This is my favorite track so far! At least until it gets techno-ish. Then it's meerly ok. 3/5
Track 6: (e1m6) What the hell just happened here? 1/5
Track 7: (e2m4) Not what I was expecting at all. Lots of chanting and cool ambience. 4/5

Intermission: Really light and funny and just plain weird. ?/5

Track 12: (infiltrator) doesn't give the level number in the title, but I've heard it before several times. One of the best so far. 5/5
Track 13: (Infected Lab) doesn't give the level number either, but it's a techno piece of crap and should have been set on fire. 1/5
Track 14: (e1m9) is starting off awesome! Another ambient creepy track that'd make me check all the dark corners. Why couldn't Doom3 have music like this? 4/5
Track 15: (e1m8) is a decent remix of one of my favorite tracks. Slow and creepy at first, it gives way to a solid beat later. Take that as you will, but I'd have preferred more creepy and less beat. 3/5

Track 16: (e3m2) is too light. This is doom, not the choir! 2/5
Track 17: (e2m6) shares the same problem. I feel like I'm at church, not out tearing things up with a chainsaw. 2/5

Track 18: (e3m8) is much better. Maybe it was just the previous two skewing my opinion, but I liked this one. 4/5
Track 19: (e1m5) is the title track. And whoo doggies it delivers. 5/5

Track 20: (text music) do-do DA do doooo. I love this song. I'm so happy! Yay! Wait. What's this? A VOICE SINGING? And singing poorly? WHAT THE spork WERE YOU THINKING? 1/5

Track 21: (bunny!) gotta love the bunny! 3/5

In keeping with Con's rating system, here goes mine.  Expect me to be more of a bastardish critic since I'm the ranking "Doom Purist" here, and I also listen to the actual Doom music on a fairly regular basis.  I'm also comparing them back to back with the original tracks to see how "far off" they go.

Intro - Not much to be said.  N/A

Track 1 - (E1M1) I like it, but the intro fades into it.  For level music I'd say the intro portion would need to be killed out which would require an edit, but I could see this working on a map.  Only thing I didn't like was the "flip channels" effect half way through, I've never liked that sort of thing in music but otherwise it's decent.  4/5

Track 2 - (E1M4) WTF, this sounds like Juno Reactor, and nothing like Doom's E1M4 music.  0/5

Track 3 - (E1M2) I couldn't tell how this related to the original at all.  The music itself is ok, but it sounds more like something from Unreal than Doom.  2/5

Track 4 - (E2M9) I can make out the Fortress of Mystery theme pretty easily on this one.  It's brooding, dark, and the bass isn't annoying at all, it's more metal-ish actual bass drum, not that synthetic Gangsta/Techno crap.  Everyone knows how much I hate annoying bass thud, and it passes the Phoenix test there.  I like it, and it would work alright for level music.  4/5

Track 5 - (E2M8) Well you can tell it's E2M8, no doubt about that.  I do NOT like the bass tones in this one once it gets about one minute in.  That kills it for me right there.  Everything in the middle is crap.  1/5

Track 6 - (E1M6) The last time I heard anything like this I didn't get the Atari 2600 cartridge fully inserted into the machine.

Track 7 - (E2M4) I feel like I just waltzed into Hollywood's version of some Druid orgy on the spring equinox.  Definitely un-Doomish.  I don't like it.  1/5

Track 8 - (E1M3) I can make out the theme, but I dislike the weird clicky effects and the scraping makes me want to claw my eyes out.  I had to stop it after a minute and a half.  Very harsh on the ears, nothing I'd want to frag to.  1/5

Track 9 - (E3M3) For those who don't know, the original E3M3 was based off a Slayer tune by the name "Behind the Crooked Cross" on their "South of Heaven" album.  This version isn't the metal thrasher I'd expect, and I think the artist is a bit ignorant of the track's history.  I'm a bit biased since I do know the history, but the track isn't bad.  It's just... too much triangle and soft synth tones.  It's too airy and spacey, and again sounds like something from Unreal.  2/5.

Track 10 - (E2M2) Another one that sounds like Juno Reactor for the most part.  It sounds like they played it on speed when it should be slow and moody.  1/5.

Track 11 - (E2M7) Nice and dramatic, I can make out the underlying tone, but the melody is toast.  Not really good to frag to, it's too "dead bodies washing up on the beach" at the beginning for that, and the piano work later is ok but it sounds like it could be people screwing on the beach for all I know.  2/5

Con - check your filenames and track numbers, you're out of sequence!

Track 12 - (Doom 2 Intermission?)  I think it's a parody of the Doom 2 intermission, but I could be wrong.  N/A

Track 13 - (E2M1) Slowed down quite a bit from the original.  Decent, but I don't understand why they keep screwing with the tempo.  Too slow to frag to, especially when compared to the original.  2/5.

Track 14 - (E1M7) 20 seconds into it and I killed it.  The bass could make my head explode, so I'm not going to bother rating this one.

Track 15 - (E1M9) I don't get it.  What does this have to do with E1M9?  E1M9's music was a rocking, fast-paced catchy insane tune.  This is slow, and more like jazz or soft rock with some "evil wind" noises thrown in.  WTF?  1/5.

Track 16 - (E1M8) Starts out sounding like A Pink Floyd concert (Dark side of what moon, exactly?)... which is ok, but then it changes into the same canned drumline that goes into everything these days.  *yawn*  2/5.

Track 17 - (E3M2) This is supposed to be the music for the "Slough of Despair".  It's awfully upbeat...  It sounds more like a TV spot where the Doom guy went on vacation and is sipping umbrella drinks on a cruise ship in the Carribean.  1/5.

Track 18 - (E2M6) I think this belongs in a Final Fantasy game or something, but not Doom, unless it's The-Scene-Where-The-Doomguy-Finally-Dies™, like they do this long, slow-motion esoteric trippy scene - until it gets to the second part.  This is WAY too RPG-ish.  It's supposed to be "Halls of the Damned" - a brooding, creepy forboding piece, not a damned funeral dirge.  0/5 for completely missing the flocking point.

Track 19 - (E3M8) Hmm... sounds like Duke Nukem.  Seriously.  This is supposed to be the fastest track in Doom, the "Blitzkrieg-facing-the-final-boss" tune to get your adrenaline up, the kind of thing you want to just scream bloody murder at the top of your lungs and start blasting everything in sight with the BFG9000 to.  This seems awfully tame in relation to the original, and now that I hear the original, I can't even remember what the remix sounds like.  2/5.

Track 20 - (E1M5) A little more tense and less creepy than the original.  At least it's not as off target as Track 17 and 18 .  This one is decent, and sounds like Doom Marines fighting their way through corridors.  It sounds like an actual movie track, complete with the "people getting killed to piano at the end".  If that's what the artist was going for, nice work.  3/5 (I would have given it 4 except I hate slow piano death music)

Track 21 - (Textmusic) Well the piano was a great start!  IT ACTUALLY SOUNDS LIKE DOOM!  But then, they had to make up words and have a singer...  She's hitting sour notes, and way out of her range, and the melodrama and phony accent don't cut it.  If they just did the metal-ish ending through the whole thing it would have been great!  But no!  YOU HAD TO TRY TO BE ARTISTIC AND !@#!@# THE WHOLE THING UP! I HATE YOU!

Track 22 - (Bunny) Meh, it's ok.  2/5

Overall verdict - Personally I think they failed miserably if this was supposed to be Doom-ish.  Most of the tracks are barely recognizeable.  A few are really good, but they don't make up for the ones that are utter crap.  Maybe I'm just too much of a purist and just too cruel, but I give it a 1/5.  That's my verdict.

I haven't had a chance to listen through this soundtrack, but I will.  I'll also jot my thoughts down on it as I'm an avid fan of the stuff put out by the guys at Overclocked Remix.  Besides the Dark Side of Phobos release, it appears that another remixer has put out a Doom remix entitled Purgatory.  It might be more to your fancy Phoenix, I'm not sure.  

And then of course, I feel obligated to pimp my favorite DOOM remix,
Gothic Sandy, which I sporking love.  The intro is part of what makes it so great, but I'm also a sucker for symphonic/orchestral "oohs" and "aahs" and singing in ancient languages and whatnot.

Update

Blargh... I completely forgot to listen to each song and write a summary.  I'll just say two things instead.  Most of what I heard was good and also a very unique take on the source material.  Unfortunately, most of the songs are so unique that it does indeed lose sight of the style of the original tracks.

Purgatory mixes some nice heavy distortion with some really nice clean parts. These work well on their own.. and I think you know where I'm going with this..

One or the other, can't do both at once..

I'm agreeing with Pho here.  Suffice to say, I'm wiping these from my drive - meh.

Regards,

Yickle.