Just did 6 dives in Barkley Sound in the Fusion with the tech skin and pockets. 41 - 43 degrees all weekend. My impressions follow - in no particular order:
1st dive was a bit tricky getting the feel of the suit and getting everything balanced out. I added some additional undies and no extra weight so was just barely able to descend and was quite positive at the end of the dive. Made for a very interesting first dive - how much air can you squeeze out of the suit??? Turns out quite a bit and I was able to do the safety stop but I was seriously cold at the end of the dive and the suit looked painted on until I could get the zipper open.
In the end comparing exactly the same undergarments the Fusion with tech skin was exactly the same in terms of boyancy as my Catalyst. I choose to add an extra layer as this was a boat dive and the water cold so dove the week 4 # heavier than I normally dive and had lots and lots of extra margin for warmth. I would suspect that without the tech skin you might shave a pound or two off.
I found the suit easier to control in the water re balance compared to my Catalyst. More leeway for feet in the air to get that tricky camera angle. The suit resists too much air in the legs very well.
Do not like the position of the shoulder dump valve. It is too high for me. Every time I used both hands to steady the camera the suit started to vent. I don't have this issue in my other suit. This will get moved to my forearm shortly.
The tech skin pockets work well. Lots of room - more than the pockets on my other suit and more streamlined. They are longer and slightly stretchy (is that a word?) so the material conforms to whatever you put in them. Two grommets in each so you can add rings or whatever.
If you put something heavy like a smb and spool of line, and you unzip the suit during the SI the weight in the pocket drags the outer skin down so you look like a snowboarder with baggy shorts - crotch down to your knees or lower. One of the few complaints I have with the suit.
Did not dive with just the lycra cover so have no comparison, but I am not sure what the tech skin really adds in terms of warmth or durability. I don't think much in either case. If I didn't really want the pockets I suspect the lycra would do just fine. Pockets attached to a weightbelt or BCD might be a better solution.
I liked the flexibility of the suit. It really does feel like you are diving in a 3 mil wetsuit in the water. Amazing streamlining, much less effort required to move the suit through the water. Didn't really notice until the last dive of the weekend as I was poking about taking pictures so not in any kind of hurry at all for previous dives. Last dive was harassed by the operator re "keep with your buddies" so abandoned the "solo diving" I had been doing and after each stop for pics swam like crazy to catch up. (no flames for solo, buddy etc. I am quite happy diving solo and they were a buddy pair) Was amazed at the streamlining, the speed through the water and how little effort it took. My Catalyst is like pushing a brick through the water in comparison. Significant and very noticeable difference. Worth the price of admission.
The front bib is annoying on the surface. The space between my chin, the reg under my chin and the suit inflator is 0" on a surface swim. They all kept knocking into each other. At depth the issue goes away completely. It may even go away on the surface if you put less air in the suit, but I like to swim on my back with as much air in the suit as I can get to keep warm for as long as possible so the bib floats up and gets in the way.
At the end of a dive if I have a long surface swim I like to get lots of air in the legs. Not possible in this suit. The outer skin keeps the air to a minimum so no starfish on the surface getting warm. Not a big deal, but something to be aware of. Perhaps if you close the valve and inflate it might work but I didn't try it.
Way easier to get in and out of - again worth the price of admission. In my Catalyst sitting on a bench and bending down to put fins on is difficult and is usually accompanied by much muttering. In the Fusion piece of cake, similar to a 3 mil wetsuit, resistance, but easily overcome. I like the zipper, once I figured out the technique solo entry and exit is easy. For the last couple of inches grab hold of the cloth behind the zipper with your right hand pull down and across and then close the zipper across the body with the left. Had no trouble at all after the third dive. Have to feel that the zipper is closed against the stop as I can't see but that is a vision problem not a suit problem.
Weights need to be tighter than I am used to. The suit is sufficiently streamlined that if your weights are loose they will slip down. Came up a couple of times with the crotch strap as the only thing holding the weight belt on. Snugged it up and no issues after that.
Takes a lot less room in the luggage even with the tech skin. 25% or less space then my other suit.
Bottom line, I like the suit and will not be going back to my previous suit any time soon. How it stands up over time is the only question I have, but I don't see any reason to suspect that it won't.