It's your thread, so since it seems okay by you, we may as well just keep talking, eh? :biggrin:
The obvious difference between the Vyper and Vyper2 is the electronic compass. You should ignore it. It *does* work, and it *can* be used as your compass, but it's harder to use than a real compass, and it uses battery power at an accelerated rate while you're using it. It's a nice backup, but that's about all I'd give it. So, if you look at the comparison page and ignore the compass, what differences matter?
In gauge mode, the Vyper2 gives you dive time in seconds. Is that important to you? Probably not. The Vyper2 has 80 hours of dive log capacity at 20-second intervals (40 hours at 10 seconds), while the Vyper only has 36 hours at 20-second intervals (18 hours at 10 seconds). The Vyper2 can also log in 1-second intervals, which gives you *extreme* detail about your dives, but the memory will only hold 240 minutes of dive time. What does all this mean? If you don't download your computer very often, the Vyper2 has room for you. If you do download often, you can use higher resolution logging while still having more time to download (or extreme resolution, if you want it).
The Vyper2 also logs your temperature every five samples, while I believe the Vyper (like the Gekko) only logs the starting and maximum depth temperatures (and perhaps the ending?). Having more temperature information about the dive is really nice, at least to me. Of course, I dive dry in lakes and quarries, so thermoclines are quite a bit more relevant to my diving. If you were exclusively diving the Keys, there'd really be little need for so much temperature data.
The Vyper2 has Deep Stops: You can set it to show you a one or two minute countdown (in seconds) at about half your maximum depth. This is just a guide, however, and does not affect the operation of the computer. (I base that statement on the fact that my Gekko, sans deep stops, mirrors the numbers of my Vyper2 with deep stops on regardless of whether I observe the deep stops or not.) It's a nice little feature, but if you can divide by two and wait two minutes or so, you don't really need it. It's just another convenience.
The big deal about the Vyper2 is the nitrox settings. The Vyper2 allows you to set two different nitrox mixes (each with their own O2 percentage and max ppO2), between which you can switch during the dive. The allowable O2 percentage in the Vyper2 is 21-99% O2, while the Vyper only allows you to specify up to 50% O2. The Vyper2 also lets you specify a max ppO2 anywhere from 0.5 ata to 1.6 ata for each nitrox mix, while the Vyper only allows you to specify a ppO2 from 1.2 ata to 1.6 ata. If you're going to end up on the technical end of recreational sport diving, the Vyper2 will allow you to specify a "deco mix", while the Vyper will not. (Either would allow you to run in gauge mode with a pre-cut technical dive plan, of course, and neither models more than two mixes or anything with helium involved.)
There's one more difference, however, which I personally consider to be perhaps the most significant difference between the two computers: The Vyper2's dot-matrix display gives you a far more fine-grained ascent rate indicator. While the block-graph ascent rate indicator on the other computers is useful for ascents, the ascent rate indicator on the Vyper2 can even show how well you're holding a hover. It's much more informative when you're making your ascent -- The Vyper2 shows your score on the test, while the Vyper only gives your letter grade, so to speak. (If the zero were slightly above the bottom, so it could also show slight descents, it would be a perfect hoverometer, but hey, they didn't ask me. :biggrin
The Vyper2 display in general is more polished than the Vyper (which is perfectly functional). The addition of the fourth button makes the control and menu system much nicer, once you get the hang of it. I don't have a big problem operating any of my computers, of course, and the manual and quick-reference cards are there for getting started, eh?
The verdict? Buying new, I really like the Vyper2. If you're pressed for cash, you probably won't be disappointed by the Vyper. Still, if you buy a Vyper2, I do not believe you would have any reason for buyer's remorse. I still love the Gekko on my right wrist, but I really love the Vyper2 on my left.
