Scuba Magazine did a round-up recently (Sept 2010, I think) and the Geo 2.0 got the Best Buy award, which I interpret as best bang for the buck. Based on that, I bought one for my first dive computer. Without the Dive Computer Training videos, I would be completely lost. The Oceanic manual was written by a committee with a truly warped sense of humor. At least they didn't waste paper on it, because you have to download off the mini-CD that comes with the package or from the website.
I am a new diver and have done only a few dives. But, I like the computer for several reasons. First, you can wear it as a watch when not diving. (It comes with an extender strap for wrapping it around your wetsuit arm.) Second, it is very easy to read. My first dives have been in a quarry with 3-6 feet of vis, and I have had no problem. I haven't caused an alarm to go off yet, so I cannot tell you how noticeable that is underwater. Third, I like the built-in safety-stop functions. If you go below 40 feet, you can have it program an automatic 3 minute safety stop at 15 feet. That has worked well for me so far.
I have not yet used the log book software with it, so I cannot comment on that.
I think the following is true for any computer with a variable rate ascent measurement like the Geo 2.0. It will tell you if you are ascending too fast. Swinging your arm up to eye-level to read it as you begin your ascent can fool a computer that you are moving too quickly. But so far, I ignore that and concentrate on watching the markers as I actually ascend. For me, going slowly -- very slowly -- from 20 feet to the surface is very important to allow the pressure to get out of my ears. So, after my safety stop, I try to move very, very slowly.
I am happy with the purchase. The computer is fully Nitrox compatible and has advanced modes for using different mixes on the same dive.
Hope this helps.
