I exchanged my two week old Vibrant for a new one on Monday because of the problems that has arisen with it on Saturday night/Sunday. I had some ongoing problems with the old one such as : GPS not working. Bluetooth not connecting and even freezing up my car stereo while trying to pair! Then last Saturday night things went downhill fast. My phone started giving me black screens that would freeze up the phone until I pulled the battery. Then my apps started having problems. I would open an app and they would work for 1 second, then immediately shut off and go back to the home screen. I was getting major lag when I tried to do anything. Even opening the contacts list took 10-20 seconds. The problems got worse into Sunday with lock ups every hour that required a battery pull to get the phone working again. Texting started to get really laggy as well. I decided to exchange the phone for another in the hopes that I got a lemon. I'm happy to report that all of the problems except the GPS have gone away. My Bluetooth now pairs seamlessly every time with my car stereo. This phone has NO lag compared to the old one. All of my apps work as they should, and texting is as fast as it should be on a phone of this caliber. The best improvement has been battery life though. This phone so far has been outlasting my old one by a large margin. Yesterday, after being on for 16 hours, my phone still had 52% charge remaining. My first phone was down to 20 or 30% by this time. Similar usage for both phones. I also noticed today that the phone stayed at 100% for over an hour, and after 6 hours of usage, it's still at 88%. I should note that the exact same apps are running on this one that I had on my old phone. Needless to say I'm very happy with my latest Vibrant. I really think my old one had a serious hardware issue. The GPS still doesn't work right, but I'm now happy enough to wait for Samsung to hopefully fix this. If you are still within your 14 day return period and having major problems, I'd definitely recommend exchanging your phone for another!