I have an iPhone 4 and tried to use AT&T service at OSH. Calls were next to impossible. Texts most of the time hit a brick wall but once in a while would sometimes go through 45 minutes to 4 hours after being sent. I was able to make a couple of calls while standing between the museum and kidventure on friday morning. Once I went through the main gates it was like some one shut off our service. I was with a couple who had verizon phones. They had some trouble but not as bad as the GSM phones.