So I dove both and here are some of my observation.
1. Weight pocket. The XDeep has more option for the weight pockets (height and size). The K2 has 4 sewn in pockets in the center.
2. Harness. both are adjustable completly. The K2 comes with a H option which is nice for steel tanks.
3. Wing. Both wings are similar in size and shape. The only major difference is that the XDeep has the central rear dump and the K2 has a lower left and a shoulder one.
I personnaly could not reach the XDeep central dump with my steel tank, Drysuit, and drygloves on. The mobility was just not there and that is very risky. The K2 is so much easier to dump and use that way.
So XDeep has a better weight management, but a worst wing if you are not very flexible.
K2 has an ok (never had any issue with it) weight system, but an excellent wing.
For me, the ability to dump trumps everything else, K2 wins all day.