With fiber in Azerbaijan, and good 2mb ADSL now, my connect is under 300 (usually around 250), so I can compare.
Take it as seriously as you can: ideas that slow connect is a massive advantage is simply idiotic. I can't even stress enough how far from reallities they are. I agree that slow connect can be advantage in very conservative b&z tactics, but it turns into disadvantage in any furball/duel situation. I became much more efficient as a dueler when I got faster connect. I started getting fun from furballs only when I got faster connect. Period.
If you do not believe me, just think about the following. It is very simple to write program, which will "catch" and delay packages on the network interface from the clien side, and thus would make your lag adjustable. This "cheating" will be absolutely "transparent" for a server. If slow connect could be an advantage, you would see lot of people "cheating" by the big lag. The only reason why it is not this way is because big lag is not an advantage. In the network playing the faster your connect is, the more fun and "natural" game is. It is the absolute truth, at least I have not seen a single exception yet.
I understand, that big lag create some problems for little lag crowd, but what you shall know, is that guy on the other side has much more problems generally, and would happily change his connect to the faster one.