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As was mentioned earlier, all computers will keep you out of deco, and you probably won't even be able to notice the difference in algorithms.
Nitrox was mentioned as a way to avoid accumulating as much nitrogen if you do 3 dives a day repeatedly. HOWEVER, I note that you mention 100-120ft as your maximum depth. If you regularly go to that depth, nitrox can present its own problems (you'll learn all about it if/when you get certified -- short version: the more oxygen in your nitrox mix, the less deep you can go and not get poisoning).
It sounds like you're a beginning diver looking for his first computer but wanting to make sure it's still a good choice later on when you do more? For that, the Suunto is a great choice. The Aeris is a great choice. At the same price I would go with Aeris simply for the user-replaceable batteries. It's also not clear what your price point is: For example, I strongly prefer the hoseless computers (Aeris Elite/Atom / Suunto Vytec) but those tend to run about $300 more.
Anyways, have fun picking out a computer.... You really will be happy with whichever you pick... Just go and dive more!
You pegged me right, i am new I want a computer to grow with. I only mentioned the 120 max. depth to let everyone know that I am planning and have only interests in staying rec dive limits. I am sure 90-100 will be my most. I only do tropical dives since I live in Tampabay, FL and maybe a few springs, but 99% tropical diving.