@tavery80
I've seen T-mobile's phone and data maps and am aware of the coverage pitfalls, but thanks for providing the link. Essentially their 3-G coverage is in all of the major U.S. markets, but that's okay, as that's predominately where most of my travel takes me.
What drive time I do have when I travel is normally on freeways, so I should be good there from a phone standpoint. I would presume if you're not in a T-mobile cell you roam on AT&T's network given the similarities, would that be correct? If so, does this apply to data (AT&T's 3-G network) in addition to phone or just phone service only?
In cities I travel, such as Waterloo, IA where there wouldn't be data service availabe through T-Mobile I'd always have Wi-Fi as an option, so that wouldn't be the end of the world.
@scrmpyjack
I am aware that T-mobile has excellent customer service and in fact recently received an award from J.D. Power as having the best customer service of all the wireless phone carriers. That's quite impressive praise.
Truth be told, I've not had any issues or problems with Verizon's customer service and I've been with them for several years after having had an atrocious time with Sprint. Verizon's been great and their network is the best out there, but their phones have always been lacking behind their competitors and they don't provide many World Phone options outside of their BlackBerry line.
I currently have a 2.5yr old BlackBerry 8830 that I'm going to ditch for the HD2. It's been a solid device but the lack of a camera and good web browser has made it obsolete. I'm also tired of the physical keyboard and since having gotten an iPod Touch for Christmas, I much prefer the virtual keyboard now to it. I know my thumbs will thank me later down the road.

Thanks for the information from both of you and if someone could get back to me regarding roaming, that would be great!