I use the React Pro and like it. It's not an expensive unit so don't expect it to have lots of features, but it does nitrox and I'd suggest getting it because the difference in price isn't that great and it'll save you from buying a new computer in the future.
Essentially Nitrox is the difference.
Some of the things I wish it did.
Ability to recall temps at different depths, or any depth for that matter.
(It does store it, but you must download the data to get it)
Not sure I can think of anything else off the top of my head. It's a basic computer, know it for what it is. The manual is available for download, look in the computer section for a link from scubatoys or from genesis support.