What would be appropiate settings for maximizing a 56k connection, I wonder. >_>

Here's where Pho and I are totally in disagreement I guess.
As long as you ping lower than 80 to a server, and your bandwidth exceeds that of 56k dialup cl_maxpackets 125 is nearly always optimal. Rate 10000 is rather on the low end of the spectrum, 25000 is recommended by pretty much all the professional quake players (and tweakers) for (Dutch) ADSL and upwards. Thus, a stable connection with 256+ kbps upload and a half-decent link to the server would be underused with anything below maxpackets 100+ / rate 20000+.

You can easily use the lagometer to test if your settings are killing the connection. A lot of yellow triangles (mind, something is wrong with the server or link to the Euro server causing hitches, so don't confuse that with a client problem!) indicate that something is amiss, and the easiest way to test this is to change your settings to the bare mininum and see if that makes them disappear. Then gradually increase the values (synchronizing them), until you see yellow or red spikes in your lagometer. If the settings don't show any such effects, you can safely use them.
Using settings on the lower end of the spectrum will always have the effect of making the game more choppy, decreasing the window in which you can hit as well as in which you can be hit, generally turning the game into more of a gamble-run. It may be my personal opinion, but I think one should generally try to avoid that if at all possible.

Futhermore, low FPS (or a strongly, rapidly varying amount of FPS) causes hitches and chops. I know this, but not the specifics - I have to rely on more fervent tweakers for details and hints about how the net system works as disclosed by those in the know.
It also makes sense when you keep in mind that the net load is affected by your FPS, and that local prediction affects the game aswell - a higher FPS rate demands more data, and then receives the data during a time when less FPS can be drawn, causing the system to get clogged. Next, a lower rate of data is 'negotiated', after which the local renderer suddenly has a lack of network information to display its frames correctly. At such times you will see great shards of yellow (or even red) spikes in your lagometer.

Concerning Kingu's connection, I know that his choppy apearance on the server has remained unchanged. He teleported all over the place during the times he used the bare mininum default settings in Quake 3, aswell as after he tried the settings I recommended, and possibly values in between - if he tried them. Since his latency is low and doesn't spike badly, the only non internet-routing related cause I can think of is FPS-problems, especially since it is known that he does 'suffer' from a low and strongly varying framerate.


I think I'm going to run some tests with Alucard later, loading CPU-limiters to drop my FPS and make him record demos me doing of a repeated run through a long hallway. That could probably clear some things up as to what might cause gappy appearance in-game. And, hopefully, what best to do about it.

That spikes yelow and red, are showing no mater what rate and maxpockets are.
 And from my side game runs normaly i don't see any choppy view, other than the others see.
 
On todays game i'll limit to 60 fps and rate, max_packets that phoenix sugested.
 Propably some help would be more ram but last time i tried to add they didn't worked with my mainboard.