Very happy with mine, but I did replace the stock fan with a quiet smart fan from Antec. CompUSA and Best Buy has them for $15 if you are interested. I think I have about $38 in the HS and I am not planning to make any more changes.
As far as the clip... it could be stronger but it works just fine. No problems at all. I would suggest that the HS be removed if you are planning to ship or transport the PC as it is pretty heavy.
Cools my XP1700 just fine. MOHAA will push it to 49-50C but under normal use it stays in the low to mid-40's.