I have this dilemma right now as well!

All the DM's I have gone diving with use a Cobra. Even in Fiji the DM's used a Cobra. It is not mentioned here. Why? Is it because it is air integrated? I hadn't thought of this issue, but understand why it could be a problem. I can't say they don't malfunction. I have been on a dive where the DM's Cobra did malfunction and became useless. Fortunately it was at the end of the dive, and he uses backups. This issue isn't something I have heard many complaints about though. Others have said they have used their Cobra for years without issue.

Also I do not own my own regulator. Do dive shops frown on needing to attach a Cobra to their regulators?

I have decided on Suunto but which one? I was thinking a Cobra w/SK7 compass attachment.

1- Cobra
2 - Vyper
3- Mosquito
4 - Stinger

All of these would work proper for my purposes I think. Is air integration the main difference?