There are worse lags on Eldar, I think.
Recently in a exceptionally big fight (something like almost 2v2 full raids) my spear gambit guilder needed about 10seconds to fire. So something like half a minute to build and use a more complicated gambit. Not to mention the problem of determining the actual position of the target and range and direction issues. Lag is bad for all classes but exceptionally awful for wardens.
Btw. I have a decent (but not this year's high end) PC and play on every low settings (except draw distance). I may do some more tricks with disabling some UI settings, but anyway it should work much better.
Warden(85), Minstrel(85), Rune-Keeper(85), Burglar(85), Captain(85), Hunter(85)