swiftech is a fantastic company making great products. I can't speak from ownership. so Idk if its a good kit. but if you google it you can easily find some reviews.
heres one.
http://www.cluboc.net/reviews/super_cooling/swiftech/H20-220Compact/page3.asp
According to that a 4ghz Q6600 will idle around 42-46C and load around 65-70C.
With you being at 3.4 though I think you'll see temps arounf 32-36C's at idle and loads of arounf 45-48 C's.
I think for 100's its a great kit with some nice oc head room.