I'm still on a Droid X on Verizon. I was going to switch it out for an S3 but I'm still fine with the functionality of my Droid X, so I decided to wait until the S4 later this year. Overall it works fine and I can still run most apps without issues. It does lag once and awhile and it does restart on it's own occasionally(about 1 a month), but that might be caused by an app that I'm running. I would suggest running an alternate launcher other than stock(Motorola Blur). I had it on Launcher Pro in the beginning but it was constantly causing force closes. I'm now running Holo launcher, for about a year now, and have not had any force closes caused by the launcher.
To answer your question it works fine but I wouldn't pay to much for it. You may get a couple of years out of it before it can't run current apps. I think you may be able to find better phones for not much more.
Also if you've never had an android device before, they are all a bit laggy, up until the latest phones so keep that it mind. Qverall I'm still happy with my Droid, but I am planning to upgrade, but I'm in no rush.
Just to let you know I use my phone mainly for calls,texts, navigation, email, camera, internet browsing and tethering, and streaming music when driving. I have a bunch of games but I now use my tablet to play them. I did encounter some games which had an issue running on my phone(to the point that they are unplayable) but run fine on my tablet.