Both class with stealth, so both are easy for cheating. Mesmer you can use for zerg running, thief no really. I didn't play mesmer, but on thief you just ganking people and flip camps (5 from pistol and oneoneone sword/dagger). Thief is funny for hunt running enemies, but don't be suprise when necro will be faster than you with 3 dodges, and short bow. Anet xmas magic.Och yea and stealth is usefull for suprise disable siege trap