T-Mobile or ATT Galaxy S2 on Straight Talk?

[Kathy Flanders]

I have my Straight Talk ATT SIM card, but haven't gotten the phone yet. From the specs and what I've read, the T-Mobile S2's are better.
I'm wondering which would be best, an ATT S2 or an unlocked T-Mobile considering I have the ATT SIM? Is the ATT on Straight Talk 4g?

 

[HNNNNNGHHH]

If you mean if the AT&T Galaxy SII (I'm assuming the Skyrocket) can use 4G/LTE, then yes it should. The T-Mobile can use HSPDA/HSPUA and Dual-channel (DC) networks but not LTE as it lacks the necessary hardware antennas.

If this doesn't help sorry. :/ The OP wasn't too clear with what it was asking.