My girlfriend and I are Mac users. Between the two of us, we have three different Suunto computers -- Gekko, Mosquito, and Vyper. If you don't mind the conservative deco algorithm, I can highly recommend them. Our dive buddies use Sherwood, Oceanic, and Cressy dive computers which are clearly more liberal than the Suunto RGBM algorithm. I don't mind it when my computer barely trips into deco mode, since I'm aware of the conservative algorithm. My buddies don't mind that we occasionally have to do an extended shallow safety stop -- probably better for them anyway.
If you're cutting tables with V-Planner, then you'll probably want a computer that has gauge mode. Of the three that we own, only the Vyper has a gauge mode. Even new, the Vyper is a very affordable computer (
Leisurepro price of approx. $325). I think
Scubastore.com sells the Vyper for $250. It is an easy-to-read, nitrox-capable computer with a push-button backlight, user-replaceable battery, and an intuitive interface. Deep Sea Supply sells a nice wrist bungee mount for the Vyper and Gekko. Personally, I prefer the Gekko's phosphorescent face which can easily be charged by a dive light...but that's just me. None of our Suunto computers have air-integration, but if you want an AI (wireless or "wired") computer, Suunto offers several more expensive models that have that feature.
With the appropriate Suunto PC download cable, we can download our dive profiles very easily from any of our Suunto computers. I bought a used Suunto serial download cable a few years ago that works with all of the computers we own. Combined with a USB-to-serial adapter (Prolific PL2303 chipset), the download cable works flawlessly in downloading profiles to my Mac. I highly recommend the donationware program called
MacDive. The developer is very accessible, and the program works well with a variety of Suunto, Oceanic, Aeris, and Mares computers. Since I have an iPhone, I was happy to find out that the MacDive SQLite database file can be freely converted to a format easily transferrable to the iPhone app called Dive Log. Dive Log is a paid program, but it works well. Now a copy of my logbook lives on my iPhone. Very convenient.
If you're primarily interested in having a record of your dive profiles on your Mac, another option to consider is to go with a separate dive logging device. I own the
Reefnet Sensus Ultra. It's very small, works great, and is very low-maintenance. It's not cheap ($175 including the download base), but consider that you'll be saving money by not having to purchase expensive download cables should you choose to upgrade your dive computer in the future. Reefnet offers free logbook software that works on all of the major system OSes: Mac, PC, and Linux. The software is simple but adequate for my needs. FWIW, in the past year, the MacDive developer began offering support for downloads from the Sensus Ultra.
Hope this info helps...