I've got the HAF XB case now, and absolutely love it. I've also got the exact same setup as you have except I'm using my 120 Seidon XL as exhaust on the back, and I have the 200mm on top also as exhause. The 2 120mm fans on front intake, of course, and the dual 80mm exhaust on bottom rear for HDD cooling.
When I stand behind the case, I can feel the airflow up to 6 feet away, and it is cool air coming at me. When I plug in my portable USB 1TB HDD, I set it on top of my case so it can be cooled by the 200mm on top. When doing a large backup, it really helps in keeping my USB HDD temps down.
Temperatures inside my case stay within 1-8 degrees C of ambient room temperature at all times. It raises 8 degrees C above ambient when I'm gaming and the graphics card is pumping out heat, which you can feel from the top of the case. The heat from the graphics card in this particular case gets vented through the top before it can get around to the back of the card where the CPU or AIO cooler sits, so there is minimal heating up of the radiator from other components, and you still get virtually optimal cooling for the CPU.
Bottom line is this:
Using this case, I get the same temps for my CPU whether the AIO cooling is set to intake or exhaust, probably because of the 200mm top fan. However, when set to intake, my GPU temps go up 3-4 degrees C. Your mileage may vary depending on actual CPU and Graphics card setup. I'm just reporting what I get with the same case, fans, and cooler.