Megahelms take up way too much of your case. Go with the H50. The temps are reasonably similar, but once you're used to an h2o loop, I imagine that it would be hard to go back to having a monster cooler in your case. I was going to go with CM's V10 but... well H50 kicks it ass and somewhat prepares me for h2o.
So, I just sold off my waterloop (to pay some bills) and I picked up the corsair H50 at bb for $60. I already have 2x scythe gentle typhoons brand new, and 2x panaflow 38mm 86 cfm fans, which are LOUD, and I would prefer not to use them, but either pair can be put on the h50 with shrouds.
My i5 can hit 4.3ghz, does the H50 have the capability to cool an i5 with great success? or would I be better with a megahelms or something?