I did some research and and decided to go with an AT&T phone with Straight Talk AT&T Sim card.
I was going to wait for the iPhone 5 announcement, but I already know I won't pay $800+ for it out of contract and I dislike the move away from Google services.
I got my Atrix HD yesterday and my Straight Talk SIM today...(Otterbox Commuter too).
I set it up with all the Straight Talk APN settings and was happy with voice, but data was a bit clunky and the Speed Test & YouTube apps were not working.
I modified the APN settings:
From: PROXY: proxy.mvno.tracfone.com
To: PROXY: 188.8.131.52
Coming from Sprint where I was getting 3-8mbps on "4G" and 200-600kbps on 3G I am EXTREMELY pleased.
It seems the ATRIX HD has a less noise cancelling than my Photon as even moving my hand around on the phone can by heard by the caller.
I tried, really tried to use the stock apps (Homescreen, Dialer, Messaging)...I lasted 2 hours. I went to Nova, Dialer One & Handcent.
I hope activity picks up on the forum and I'm sure I'll be posting regularly...for awhile at least.