bigger fan = more air less noise (better), wusy is exactly right, and I echo him... why the hell would you want to use a 70mm fan on that heatsink???? I think that's the biggest flaw on the Tt 7+!
As for the heatsink itself, I own one, certainly no other complaints here. I have OCed all my cpus and never had to go above the low setting - which is very comfortable for my ears. My highest temp ever has been 42C on my current cpu which is a 2500+ barton running at 3200+ @ 1.8v.