It does lagg sometimes, havent been online much today, but u always experience a small freeze or something when ur playing. Thou I cant agree with Goten, saying that it lags ALL THE TIME or that u die cuz of it..and no, the loss due to death aint alot..especially not with blessings. Im lvl 356 and I died just a few lvls ago, and I lost 1 lvl and a few % on each skill, not much to complain at since u take it back within 20-30min without any probs at all.
Anyway, yes it does lag SOMETIMES, atleast thats my and my rls experience, and yes, sometimes/some days, its more lags than usually.