I've been using MacDive since the 1.x series and some weeks ago updated to 2.x. I just love it.

Right now there's just one thing that annoys me a little bit: when I'm going to import a new dive, I have to go to the Import menu and then down to the Vyper2 option. I think it would be great to have an "import new dive" button on the UI, which by the way would need an option on the config to set your default computer.
BTW and UI-wise, I'd "expand" the gear button into a 5-button group with its 5 options. One less click.

Regards