I am looking to refresh my computer a bit and I am considering push pull on my NZXT Kraken X62 (280mm) and also maybe my 1080 Hybrid, mainly so I can run the fans slower and perhaps increase the performance slightly.
Only thing is my computer room seems to collect dust very quickly! I am going to cut down the computer on time when it is not needed and I do weekly dust filter cleans as it is so hopefully this will help, so push pull will obviously make it a bit of a pain to fuill clean as I will need to remove the fans.
My first build I did I had a Phenom X4 955 BE overclocked and all I had was a deep cool ICE BLADE 200M. I recommend that cooler and push pull to everyone now. It kept the chip at load at 40 deg C.
It really depends on your radiator specs as to how much performance you may gain from a push/pull configuration. If your rad is really thick, like an Alphacool Monsta, or if it has a high fin per inch count, then a push/pull configuration will increase your cooling performance. That's because it doesn't increase the amount of air flow, but it does increase the static pressure which is what you need to push the air through a dense radiator. AIO units usually have medium fin density so it may pick up some, but it might improve just as much by selecting some different fans with higher static pressure.
I have a Monsta 360 in the front of my case with push/pull fans. The rad is 80mm thick and the fans usually run at about 1100-1200 rpm on my silent profile while gaming. I have my cpu, 2 gpu's, and another rad in the loop so my performance numbers wouldn't be applicable though.