You may have noticed the update on our Epic 4G review from yesterday where we lauded the fact that Samsung seemed to have fixed the GPS problem plaguing every other Galaxy S flavor released thus far, but it turns out there are actually two distinct issues.
I've been using Samsung's Vibrant (T-Mobile's subsidized Galaxy S) and yes there's an issue with GPS. It takes a while to get GPS locks if you're inside a building or in the bus in San Francisco. It just takes forever, or even worse it freezes your phone and force reboots.
If you're walking outside without any tall buildings you can often get a lock pretty quickly so I don't think it's a broken hardware but an issue with software/firmware. For now I disable GPS most of the time since I don't drive a car and don't need GPS navigation. Wireless networks based location service just works for the most of my use case such as Maps, Yelp and Foursquare.
Hope Samsung fixes this with the firmware update with the Froyo release in September.