Ditto others. I own two Sports, two Pros, and two Nitrox Pros. They are my favorite computers by a long shot. They provide all you need. Easy to use. Easy to read. And, most important of all, rock solid bomb-proof reliable. I have owned some hockey puck computers--Genesis Resource, Aladin Prime, Aladin 2G. All things considered, I'll take a Sport or Pro when diving air or a Nitrox Pro when diving EAN any day. When I dive one of my Aladin's, I never even think to carry a backup computer. When I dive my Aladin 2G, I will not enter the water without a backup computer, either also on my wrist or in my pocket. (But eventually I hope to be able to do away with a computer altogether--but I am not there yet.)
Negatives: As people said, battery life is computed by an algorithm that has nothing to do with the actual life of your battery. Moreover, battery replacement is expensive--right now, if memory serves, ~$130. Also, water temperature is not displayed. I believe the computer uses water temp in its deco calculations, but water temp is not displayed. I might be wrong, but I think you might be able to download water temp info for a dive using the Data Track or Memo Mouse or whatever is the one that these older Aladin's use (I have never bothered).