It used to be 20000 (though you used to stumble upon those people every now and then who were hallucinating about it being '25000') and now I heard it's not capped like that anymore, that you can use the values up to 10000.
Do they servers support this though? Or was it (is it) limited only on the client-side and what do servers do should not be of our concern (apart of setting it up properly, i.e. giving the 'sv_maxrate' '0' or '100000' value)?
Should I use 100000? Should I setup all the servers to use 100000 as maximum, as well?
No, as long as you and the server can transfer data between each other at 100 kbps (that's what I think 'rate 100000' stands for) steadily, it's not the case. I mean, the reason why they say in all those outdated guides (like the official instruction that is bundled with the game) that you should use lower (as low as 2500) rates on 56k dial-up connection is that that's the actual speed of a dial up.
Isn't 'rate 100000' the equivalent of downloading a file with a speed of 100 kBps? If so, then isn't it like virtually everybody nowadays is able to download files with such a speed? At least everyone who would you his/her connection for gaming. And isn't 'choke' caused by the server not being able to send all the data? I'll have more choke if you lower your rate (in any case and on any CS, after or before the update, even 1.5 =D).