Re: Captivate GPS
GPS on my Captivate is nails using any of the i9000 Froyo roms and modems. The latter of which add HSUPA capability on AT&T's network, btw. If you can't get a GPS lock you probably need to enter LBSTestMode with SGS Tools and double check that the SUPL settings are correct (supl.google.com and 7276). You then have to delete your GPS data and reboot the phone and you should get lock within a few seconds.
I routinely get 10 sats to lock on my location within 3 meters while sitting on the couch inside my house.