Extended Roam - Digital vs. Analog Question

I recently moved to VZW and purchased a trimode phone because an area I frequent was added to "extended digital" coverage. I was there over the weekend and had very little digital coverage; only analog which was poor at best - couldn't follow any conversation on either end.

I tried to switch from A to B w/ no luck and can't (or don't know how to) "force" digital only on this phone. I asked the VZW store why their coverage maps show 100% extended digital and they said "Oh, that area is almost all analog"! I'm not talking a dead zone, I'm talking 100 sq. miles or so!

Anyway, I'd be willing to try an all digital phone to see if it will work but I don't know if that will help. Does analog "trump" digital even where its available? Or, if I'm not receiving digital on the trimode phone does that mean it simply isn't there?

My phone is v710; the area in question is NE lower peninsula of MI. Initially, I did receive extended roam digital via SID 244 but, as I went north, it changed to only analog on SID 1337 (once 1338). At one point, I had a digital roam signal on SID 1337. That makes me think that there is simply nothing but analog available -i.e., trying an all digital phone won't do anything for me.

I only have 3 days left on my trial...any suggestions? Thanks.