I have great results with the EX right now. I have my 1100T @ 4.1ghz, 1.525v, and my GPUs are at 1020mhz core, 1.188v. My CPU runs probably 7-10* cooler with the EX+RS setup. When I added the EX, I also added 2 gpus, so thats worth thinking about. I can get idle temps (FWIW) probably 2* over ambient, and my load temp in prime doesnt go above 45* now, usually around 42* (prime95/IBT)
In BF3, all ultra (no MSAA) at 1080p, my CPU will stay around 35*, and both GPUs are comfy at 40-41 and 43-44, not sure why one runs warmer than the other, they are in parallel.
I have yate loon high speed 120mm fans in push pull on both rads, probably running about 9-10v (on a rheosmart 6). I am *very* pleased with the EX360, especially considering the price.
Also, FWIW, I have my loop going pump -> GPUs -> EX360 -> CPU -> RS360, and the CPU runs cooler than before when it was just the cpu and rs360 combo...