iPhone4 prepaid GoPhone or Straight Talk?

[tedshred]

Have seen a few threads on this topic, but nothing seems like it's been posted since at&t added their prepaid smartphone plan ($65/mo. unlimited talk, text, 1 GB data). Also most posts on prepaid don't seem to talk much about keeping the same wireless #, which is important to me. Here's the details:

I have an off contract iPhone 4 on AT&T. I want to switch to a prepaid plan for more services less $$ (currently on a plan w/ no text and 200 MB/ mo. data for about $60). I’ll probably do this for a year or two before upgrading to a new iPhone I’ve researched that many people are happy w/ Straight Talk pre-paid. I’m also considering AT&T’s GoPhone pre-paid Smartphone plan even though they don’t officially support the iPhone on that service. If I go back to a post-paid plan w/ AT&T, it’ll be easier to switch the # back if it’s already w/ AT&T. Have submitted a request to AT&T to unlock my phone as well. Hasn't been approved yet.

Concerns w/ straight talk

• Complaints about porting your number from straight talk if you switch carriers again
• Is MMS supported yet w/o jailbreak?
• Not a fan of Wal-Mart, prefer to do business w/ other retailers

GoPhone questions

• Activation for iPhone data on GoPhone:
• Will I get blocked on data automatically b/c I’m porting a number from an existing post-paid iPhone acct?

An AT&T retail employee said that data doesn’t work on iphones used w/ Gophone. Heard of a couple workarounds to get 3G data to work w/ GoPhone:

• Use IMEI of an unused GoPhone or just enter 0’s in place of a real IMEI #, which trick is best to get 3G data activated?
• Sounds like MMS works on GoPhone without a jailbreak, true?

Thanks for any info out there on using 3G data w/ GoPhone and feedback on Straight Talk & MMS. Merry Christmas!!