It really is all about budget and personal preference.
I think once you make the move to a wireless computer, you won’t look back. I imagine if maintained properly, they would have the same failure rates as standard computers.
I think one of the important factors to look for is to make sure that it has a user replaceable battery. Also make sure it has all the features that you need to cover whatever diving you are doing now, and in the future.
I personally have the Aeris Elite T3. While I think this is a great computer and happy to have it, the one thing I wish it had that it doesn’t is a compass. That and the slimmer profile of the D9 has made me reconsider whether or not I should have ponied up for the D9 up front and then called it a day.
The other advantage is that you can actually wear the D9 as a regular watch when not in the water and no one would think anything of it. Try putting on my Aeris Elite T3 in public and people would think you had some sort of medical problem.
I don’t have unlimited pockets either and the price difference between the D9 and the Aeris Elite T3 was significant. At the time I think I got my T3 for just under $700, and the D9 was $1300. Is it really worth the extra $600 for the compass and slimmer profile? Not so sure I could have justified that. But if I had looked at the purchase as both a watch I could wear 24x7 and a computer, I might have reconsidered.
Just my thoughts...