The Aeris elite is a two button computer only. I have one. Let me start with the pro:
1. Lots of features, probably a recreation diver would ever need
2. It also has a gauge mode, so it makes a very good backup device if later you move to a newer computer.
3. Good built quality, tough. It is better than Uwatec Tec2G which I also have.
4. User replaceable better, battery type is also very easy to find.
5. compatible with DSS boot.
6. although not small diameter wise, but not "thick". Thinner than Tec2G.
Now the cons, which I think OP would be more interested:
1. for its age, the strap will probably going soon, so you will need DSS boot or new strap.
2. the shape of the module itself is not a perfect plug like Tec2G or Mare Plug. This make putting it in DSS boot a bit of struggle, putting quite a bit of stress to the DSS boot. If you only need to do it once, it is fine. But you need to take it out of the boot to replace battery. So far I did it twice only. I don't know how many more times the DSS boot will stand up to this. It would be suck to replace the boot ($20)
3. battery life isn't particularly good. The manual says 50 dives, it is quite accurate. Consider #2 above, longer battery life would be better.
4. Battery icon doesn't tell battery level accurately at all. It can show you full battery in the morning, then death after two dives. So you better keep spare batteries in your save a dive kit. Have that said, this is not a unique problem to this computer, but rather common on AUP computers.
5. Minor, but important to me, gauge mode does NOT show seconds. This is why I also have Tec2G
6. Minor, I personlly think Aeris/Oceanic software for dive log download sucks. I already gave up on it.
Overall, I think it is a good computer. I have no issue of its operation under or above water. For a good price, I would not hesitate to get one.