My innards went back into my P180, shortly after my R3 purchase.
CPU/ GPU temps were about the same, given identical fan configurations (two 1200 Slipstreams @ 5V at rear/ rear-top); I was hoping for much lower temps on the R3, given its apparent increase in intake area (by means of the bottom vent).
Without resorting to any DIY means, the R3's drive sleds were poor in dampening HD vibrations. Seeks from my Sammy F3 could be felt - not to mention heard- along the chassis, with a mild resonance. I suspect drive suspension would be a lot easier to do though, in the R3's case.
The top section of the case felt very flimsy, and would flex under the slightest downward pressure. ("But but, the case isn't supposed to be a stool, dummy!" I know, but this doesn't inspire much confidence, either way. Make sure you have smooth fans, if running up top.)
The bottom fan filter's "fabric" would rub against the fan blades, producing a high-pitched sound.
The front fascia's plastic felt much cheaper, in comparison to the P180.
I'm not going to get any further on this, but the R3 now resides at my ex's condo. It's a nice case for what it is (looks awesome, has great features which should be implemented by the P184, should the time come), but after working with the P180, it's hard to settle for something as flimsy as the R3 (I had to pry the sides off forcefully with a small slot screwdriver every time, FFS).
I hope this doesn't detract from your purchasing decisions though, guys/ gals. Consider this contructive criticism for Fractal Design. I wish them all the best, truly.
With that said, I've been eyeing the XL for a long time now. Might drop by NCIX to see if they have any on display; hopefully it's much more rigid than its R3 counterpart.