I'm also looking at several computers and have aspirations similar to yours (diving beyond recreational limits). I looked at the the Smart Tek and it seems like a pretty trick computer, especially with the 3 gas capability; however, That means I would also have to buy 2 more transmitters at ($300 to $400 apiece) in order to take full advantage of it. That adds up to about $1600 to $1800 (the computer with one transmitter is around $1000). For that much I could get a top of the line VR3 or Abyss Explorer. Interestingly, these trimix computers are not air integrated (but can read PO2 levels from CCR's).
I've only been looking into tec diving for a few months now (mostly via internet) but non-air integrated computers seem to be the norm. I'm not sure why but could easily make some guesses. For example, with an air integrated computer (hose or wireless) you will still need SPG's for backup on all your mixes. Also, there are only a few computers that can handle mix changes. So perhaps advanced equiopment equals lots of extra stuff. I've read that many tec divers just use an SPG and bottom timer and dive their planned profiles, which is what you would do anyway, even with a fancy computer; so, why waste the money on a fancy computer when you could spend it on helium or something else more essential (staging tanks, etc). Just a guess.
After researching a bit, I've decided I still will get a wrist mounted computer because that's what I want for my current level of diving. I looked at the Dacor Darwin and Mares Airlab, air integrated, hose mounted computers because of some opinions that wrist mounts sometimes get in the way and because I can get one for half the price of a wrist mounted, air integrated computer but have almost decided against it. I may forgo the air integration and just get a wrist mount, in which case it will be the Aeris Atmos 2. I have an aeris XR1 now and will be able to use it as a backup since they both use the same or similar decompression models (something you may want to consider yourself if you haven't already). For the same reason, I will probably get an Aeris Elite if I go the air integrated route.
Well this was a bit verbose and I don't know if this helps you but writing it down is starting to help me figure out what I want. As for using whatever I get for tec diving, I'll cross that bridge when I come to it (I suppose you can always use just the computer part of an air integrated computer, besides, ultimately I think I will get a VR3 or Explorer). In the meantime, I really want a wrist mount.
-Bob
