Just wondering guys and hope to hear your input. I am grandfathered on AT&T unlimited data 6 months into new contract that ends in Jan 2014 and pay $78 a month. Was thinking about breaking contract to go to StraightTalk for $45 a month for unlimited everything. Early termination fee would be $275. I heard on StraightTalk you get 3G speeds and everything what do you guys think and any experience.
I was in almost an identical situation. I upgraded to the iPhone 4S in February and renewed my AT&T contract for another two years at that time. Grandfathered unlimited data plan. I was paying between $65-70 a month (depending on per-use SMS charges) thanks to a FAN discount through my employer.
I found out about Straight Talk's bring-your-own-device plan a few weeks ago and started seriously considering it. I ended up switching to Straight Talk a couple of weeks ago, and so far so good. I obviously haven't been with them long enough to speak about data limits or throttling, but then again, my peak month with AT&T over four years was only 1.2 GB, and I averaged closer to 700-800 MB most months, so I doubt I will ever have that problem.
The switch itself was really easy and smooth. I ordered the SIM card kit from their web site (beware: they require an in-person signature upon delivery). I activated and initiated my number port online. It was all complete within 10 minutes, and this was on a Sunday afternoon.
I get full "4G" using a Straight Talk AT&T-compatible micro-SIM. I have noticed no difference whatsoever in terms of coverage or speed since switching, which makes sense -- I am still using all the same towers I was using as an AT&T customer. I have not yet received a bill from AT&T for my ETF, but I'm sure it will arrive soon. Once I've paid that, I plan to call them and get them to unlock my iPhone per their new unlocking policy.
The biggest downside (for me) is the lack of visual voicemail. However, I set up a workaround using Google Voice and conditional call forwarding. All missed/rejected calls get forwarded to my Google Voice number, so I can still have "visual" access to my voicemail that way. The lack of MMS doesn't bother me; I haven't even tried to use any of the tricks mentioned at Howard Forums for getting it working. Most of my friends who would send pictures are already iPhone users anyway, so it would go over iMessage rather than MMS.
The biggest caveat is this: even though your AT&T account is "post-paid," it is actually billed in advance, and I found ample complaints online that AT&T will not credit you for unused days if you terminate your account mid-month. I don't know for a fact that this is true, but just to be safe, I waited until the next-to-last day of my billing cycle before initiating the transfer to Straight Talk.