Been lurking here for a while, but I'll pipe up now.
Deep Outdoors Matrix is pretty much a "modular" system you can build to your specifications. I was shopping for a Halcyon wing and BP when I came across Deep Outdoors and started looking at it. From what I'm told, Deep Outdoors was started by some former Scubapro people.
The Matrix is definitely not DIR, so if you're looking for a "stock" DIR system, stick with the Halcyon wing/BP setup. However, the Matrix is customizable. You can detach the BP from the harness and pad, buy yourself a single piece of webbing, and build your own harness to DIR spec. The backplate is a nice laser cut 7lb SS plate. I haven't compared it side-by-side to the Halcyon (or Fred T's for that matter) to check the possibilities for harness placement.
The Matrix harness has a ton of rings and buckles. That's one thing I really don't like about it. Then there's the plastic quick release buckles, chest strap and belly strap. The main waist strap is a SS (I think) buckle like on the Halcyon harness. The plastic is some composite material that is supposedly fairly strong. We beat on the plastic with a hammer and it didn't deform or break. The harness fits like a tactical load bearing vest and is quite comfortable.
As for the wing, my first impression was "are you trying to get me killed?" They looked like the infamous OMS bungied wings of death--especially on the orange 85lb wing I saw. However, the shock cord in the wing is light latex and it does not collapse the wing. The wing will not fully deflate by itself. Supposedly, the wing will keep about 10lbs of lift in it unless you're trying to force the air out of it. I suppose that at depth, it would flatten just like any other wing. As for oral inflation, it took a handful of puffs to inflate the 85lb wing full. I didn't notice much difference in oral inflation difficulty between the DO and Halcyon wing.
The DO has an option weight system you can add on. One is a "front release" and the other is a "bottom release". The "front release" system is downright dangerous. I stood in front of the BC yanking on the weight release system to try to get it to ditch, and I could only work the system using both hands. It would be nearly impossible to quickly operate the weight release system underwater and under stress while wearing gloves. Avoid the "front release" system like the plague. The SSI instructor I was chatting with actually apologized for having the front release system on the floor, as they had decided to ship all the front release pouches back to DO because they sucked. The bottom release worked pretty smoothly, though.
I didn't notice any provisions for trim weight placement like the Halcyon setups I've seen. I suppose it could be done, though, since you can buy all sorts of keen pouches for the Matrix.
I thought it was one of the better BC's I've seen lately, as far as "mass marketed" equipment goes. It's still a "techreational" BC, though. If DO were to shed some buckles and eliminate failure points, I'd be much happier with it.
