That is completely wrong HooPZ. I've used the peer to peer kaillera client quite a bit, as well as the basic server based kaillera client to play on MAME.
The p2p client is very good, Good enough that very frame reliant fighters are worth playing. Super Street Fighter 2 Turbo, Street Fighter 3: Third Strike (i've had people full parry supers against me before), etc.
Definitely check out the p2p client... The server based ones are alright, but the lag can get really bad