I just bought the Galaxy S3 about 2 weeks before they announced the S4 coming out. I am with T-mobil and previously had a motorola defy. It worked GREAT, and got both good WI FI and network reception with T-mobil. Now with the same T-mobil account, my Samsung S3 doesn't get any network reception in about 75 % of the places I used to get it with my motorola defy. I even got a signal booster to put in my home, and it still doesn't help. I just paid $600 for this stupid phone, and can't use it most of the time. I am missing calls from my kids, and can't call them when I need to. I have the latest update, and doesn't make any difference. My husband has the Galaxy S2 and has NO issues. It works fine in all the places my S3 does not. This S3 sucks!!!! I will have to eat the $600 and buy an S2 or maybe try the S4. Really dissapointed!!!!!