Is Straight Talk a good unexpensive carrier of Iphone (At&t compatible)?

I have an iphone 4 (GSM) and I'm considering using straight talk since it its fairly cheaper than regular At&t plus I don't use the phone as much data-wise (say close to 300 mb a month).

Has anyone have had good experiences using this service provider (in terms of phone signal and data usage - less than 1 gig of course).

Added (1). Please provide good answer with some detail in your area (maybe city and state wise and rural vs suburban). That would be very informative. No SPAM please

To me yes

StraightTalk is very cheap compared to other providers, and their phones operate fairly well. Beware that signal while using StraightTalk may not always be that great, so if you live in a rural area, it's not for you. If you're looking for a good price, $45 a month for unlimited talk, text, AND data is hard to beat, but I believe that StraightTalk is unreliable. Also, their customer service is TERRIBLE. Worth it for me though.
Also, don't believe it when they say that they let you keep your 4G service if you had it with another company. It says 4G but it's really just 3G, self tested.