In 2007 it's a bit dated, but it still offers an intangable charm that most MMOs simply don't have.
While I haven't played AO extensively, my 3 months of play time was more enjoyable than most MMOs I have played. It's not a polished gem or a gem at all for that matter, but its character flexibility and community make it an enjoyable playing experience.
I refuse to spend to much time dwelling on a game that's closing in on nearly a decade in age, but I felt the need to give this game a thumbs up for those who are looking for a sci-fi MMO in a market over-saturated with fantasy themes. The best part of AO at this point is the free-to-play option that is currently available. While you won't be able to get the best gear and miss out on some content, you can still have a lot of fun with the free-play version. So, if you are a cheapskate like myself, AO may offer you 30 - 40 hours of fun.