Mesmer : Lintar M
So when?
S/P thieves? i rarely see them in WvW, sometimes play it for some fun bursting or the extra interrupts over S/D
most S/P thieves are rather predictable and therefore pretty easy to beat imo though, only problem is the extremely high burst of some (which is the same with D/D where you can also easily dodge their C&D+Steal combo if you see the animation)
PvP, Teef & Engi