I've been diving a Fusion with the Bullet skin for a couple years, about 180 dives, and was a vocal fan praising innovation and all that. And then I switched to an old school DUI for improved flexibility.
That's right, flexibility. Fusion is flexible in the sense that it's soft and easy to fold to pack into a bag. I was very surprised that my own flexibility doing the valve drill (shutting down and opening the valves on a doubles manifold) was much better in an old school drysuit. I did my tech checkout in a Fusion, and it took three months of stretching before I could reach the left post, still with much strain. Then the neck seal ripped on my Fusion, I sent it for repairs, rented a TLS 350 and was stunned to find that the valves suddenly were "right there".
What's going on here is that a stiff fabric of a traditional suit does not resist you movement at all, as long as it's baggy enough to allow the range you need. An elastic skin like the Bullet always starts pulling back as soon as you move away from the "normal" position--a little at first, and the more the further you go. Plus, an elastic skin compresses your undergarment which makes it a little stiffer as well. Incidentally, I also found I was a little colder wearing Fusion, again because the elastic skin would compress my undergarment more than a traditional suit.
So counterintuitively, a stiff suit can actually make you more flexible. It's all very personal and depends on your build, the suit cut, the undergarment, the gear and the type of diving you do. There is no objective "flexibility", no matter what Whites marketing may lead you to believe. Few of us need to do splits underwater. The best you can do is test-dive some suits for yourself.