OK, I'm the market for a used computer. I want AI, but can't afford wireless... That means a console unit, so I guess I'll want QD and a compass on it too.
Sherwood Wisdom 2 - Not a lot of these on the used market. it looks like there are a couple different versions out there:
Sherwood CG7125 2008 Wisdom 2 Dive Computer with Compass and Quick Disconnect
Sherwood CG9125 Wisdom 2 Dive Computer with Compass and Quick Disconnect
I own the Wisdom 2 for close to 3-years now. Supposedly there are some minor improvements between the Model #9125 over the Model #7125 (my computer), but I don't know what these improvements are.
I've also owned and used my Wisdom 2 #7125 for about three years. The newer model Wisdom 2 #9125 supports a deep stop in addition to standard safety stop, and has double the memory of the original Wisdom 2. They also changed the computer interface, however, requiring a completely different cable than the earlier models used.
If you buy used, you can tell which model by the button color: grey=original Wisdom; aqua=Wisdom 2 #7125; chrome=Wisdom 2 #9125. The older two models use the same cable, the newer one needs a different unit.
Anyway, I love this computer because it's so easy to use. One button activates it and another button for lighting up the display at night. Big, easy-to-read numbers. Easy to navigate menu. Supposedly even the downloading is easy. I don't download mine, but my buddy with the same computer does and he hadn't complained about the downloading procedure in the two years that he owned it.
I would recommend the Wisdom 2 for all the same reasons. Big display, very easy to read and operate. In fact, I got it because it is very simple and intuitive; I don't want complexity underwater.
I would also add to the list of positives that the battery is common and easily replaced, without the computer losing it's memory or settings. And it's long-lasting, I changed mine after two years, 100+ dives, not because it was getting low but... well, just because!
I have the add-on compass, which is fine. I wish it were digital and integrated, but the analog compass reads easily, settles quickly, and reads from several angles (top and side).
I download regularly. It's sometimes a little testy getting a good connection, but still I'm going on 200 dives with it and only one incompletely downloaded dive. The newer model supposedly fixes those problems, but like I mentioned it requires a completely different cable.
Weaknesses of the Wisdom 2 include the dive log software, which is OK, but can be glitchy. Make sure you download the latest/greatest from Sherwood's site; don't trust whatever comes on the CD.
Finally, something that could be either a pro or a con, depending on your perspective: The Wisdom series definitely uses one of the most aggressive algorithms out there, possibly
the most aggressive algorithm. This means diving the Wisdom will often give you longer no-deco times at a given depth than most other computers. But it also means you
really shouldn't push those limits on the Wisdoms. Seriously.