Just try it out I guess.

Probably the latter. For me it was speeding up fairly well on a 38Kbs dialup and lagging noticably on ADSL. The only drawback I have now without MCCP is that the server seems to send the balance/eq recovery message and the prompt following it in separate packages, so there's a delay between balance recovery and the next prompt appearing. With MCCP it must've been sending them together, since I can't remember ever having this problem before.