Not boring you all with pictures you can see anywhere on the internets reviews. This is just before and after.
This is my upgrade from an H50(left) to an H70(right).
The backplance and retention bracket is EXACTLY THE SAME as the H50, which makes upgrading that much easier, in my case.
The power cables for the H70 are NOT braided, like the H50, and for the fans are 3 pronged, instead of the 4 prong one for the H50, but they come with thingies to change the RPM manually (which I didn't install). There is a Y-cable so you don't have to get another connector because of upgrading from 1 to 2 fans. Of course it is louder than the H50 because you have 2 fans instead of one.
I have them blowing exhaust just like the H50. I don't have the airflow going into the computer because I don't have 3 GTX480's sucking up the airflow (that and I only have one exhaust fan, to the left of the CPU). I can't put the rad on the back because of the fan on the southbridge for my mobo, which I would have the H70 intake and fans on the top for exhaust.
I've seen another person with an H70 and an 800D do the intake in the middle port on the top of the D800 and the 2 side ports on the top are exhaust. That's a bit much, and I don't live in Spain where it's 35C for 9 months of the year.
TEMPS In Celcius (Ambient 24C)
H50 H70
33 31 800Mhz (Power saver mode idle)
36 32 3.0GHz (idle)
51 45 3.0Ghz (Prime95 100%)
The H50 is going into my Jesusbox so I can now unhook pretty much all the other fans and be decently quiet-like.