Picked up a pair, and after playing in them it's going to be really hard to use anything else.
I play PG, like to drive a lot. I would best compare my style to TJ Ford.
Sizing
Got my regular size, it fit fine. Probably could have afforded to go down a half size but the 10 felt right.
Comfort
Absolutely great. One of the most comfortable shoes I've played in, the only thing was a tiny bit of side to side movement, but it wasn't anywhere near enough to have me worrying about my shoes more than playing my game. I didn't have problems with breathability but I was wearing Dri-Fit socks.
Ankle Support
Once again, great. Fit at the ankle is very good but manages not to be overly restrictive. Ankle support is usually not a factor for me when choosing a shoe but the XXI actually made me feel more secure than usual.
Cushioning
The IPS system from the XX carries over to the XXI as well and still continues to amaze me. Court feel was improved from the XX in my opinion which just makes it even better to play in. I thought I'd like the Zoom bag (red) because I love shoes that use Zoom but after playing I actually prefer to use the Encap. Air pod (black). It just felt more solid under foot. The Zoom pod was more responsive though.
Traction
Last but definitely not least. Traction was excellent. I was able to stop on a dime, you can definitely break some ankles in these. It was definitely a drastic improvement from the XX's translucent rubber pods. I would say that the XXI's traction is almost on par with the XVIII's.
Overall
Comfort - 5/5
Ankle Support - 5/5
Cushioning - 5/5
Traction - 5/5
I would recommend this shoe to anyone who is thinking about them. They're suitable for all postitions. The one turn off is the price but I really can say that you're paying for the best performing shoe.