Follow up and update from my end...
As a quick update...
After receiving some confirmation, the Asus PadFone will work on US T-Mobile's data network...with EDGE/2G only.
Yes, I am quite disappointed in hearing such. AT&T's data network was not the greatest either with EDGE/2G only as well.
That said, I moved forward with just the Google Galaxy Nexus (vs. combo with the Nexus 7 tablet). I have unlocked and rooted it. I now have CyanogenMod 10 running on it from the daily builds quite nicely. I do wish there was a way to curb the GPS battery usage (which is a major drainer!), so if and when I do use this feature, the Galaxy Nexus is on the USB cable in my vehicle to avoid death by battery drain. A one hour road trip around town to test it out, I was down 40% of the battery and still going being eaten away.
Outside of that, I do like the fact that the Nexus is not carrier locked and has some (note "some") better hardware under the hood to be "carrier portable" internationally if and as needed.
The reason for just the Google Galaxy Nexus and not also the Google Nexus 7 tablet at this time is this is...my first "smartphone" and Android device. Yes, I know...hard to believe and such...however, this is a nice "first choice" as well.
With my occupation as a Linux trainer and Open Source consultant (systems administration/engineering oriented) the Google Galaxy Nexus with my laptop will do what I need to do 100% of the time. A separate table would be "extra weight" in my personal case, plus another added device of "where is that file again?" situation for me if it is not on a cloud storage like system (which yes, I have one via my company directly).
Maybe Asus (if not others) will take note from Google's mind set and make a PadFone that is "more carrier portable" or "carrier neutral" or just plain "open".
***gets on the business marketing soap box...temporarily***
After all, a GSM pentaband for voice and data will cover most of the US, Europe, and parts of Asia which is a large and quite diverse market of customers.
***gets off the business marketing soap box***
Oops, I said that out loud.
Hope this helps others going through similar consideration and explorations.