I've considered this kit/setup a number of times, but always end up getting worried that it's going to vibrate loudly as so many 5¼" pump/res combos seem to. How are you finding it?
Also, with this case, my issue with a dual 5¼" res is that I wouldn't have room for a fan controller, optical drive (yes I still use one) and some form of USB front panel.
Vibration is not too bad, the most noise it makes is the water hitting the res when it returns.