These computers can do incremental nitrox percentages up to 40%, which is what the CMAS Nitrox Diver cert qualifies you to do, so you'll definitely get many years of diving out of one of these until you progress to Advanced Nitrox or whatever.
Several people in the club have one or similar (i have an older Suunto Vyper which i bought off Lenny, it's the only piece of diving kit that hasn't broken on me yet
)