I bought a Captivate from an original owner for $100. At first I was not all that impressed due to what is termed around here the "Galaxy S Lag" (a persistent inability to rapidly respond to screen clicks, etc). I upgraded to Gingerbread, which didn't help the lag and added the "TetheringManager Bug" to the phone (great! ahhh!). I finally got sick of the TM bug and the lag, took the time to root the beast (as per forum guide here: [Guide] Root for Official 2.3.5 With Guide
), got rid of the AT&T bloatware and TetheringManager, and now it is working very nicely. No TetheringManager crashes, and NO LAG! Totally wonderful! It will always be an old, out-of-date beast, but I have some very nice out-of-date hardware that works great! Now my Cappy can be added to that list.
I hope this helps.