Hey, nice plug. Subtle.
I have a JASJAR connected to my corporate Exchange server using Vodafone as the carrier. Based near Manchester I regularly travel down to the south-coast and south-west of England, as far north as Fife and well into Wales (north as far as Caernarvon and Anglesey, and south to Cardiff). I also happen to spend a fair amount of time on the M4 (but then doesn't everyone who travels on the M4...). And my GPS makes sure I experience all sorts of interesting geography.
Anyway. I can honestly say the only trouble I've had with coverage is in the following situations:
1. On holiday in a rather remote cottage in Rowen in North Wales. Actually, I think Rowen was fine, it was probably the cottage walls because the coverage was just about OK by the kitchen window. Guess I shouldn't have been checking my mails on holiday...
2. At about 5pm most Friday afternoons in my home village I tend to have trouble sync'ing until about 7pm. Everyone txt'ing and calling home to apologise for being home late for tea. However...saying that, this seems to have improved lately and I notice our local mobile mast has been getting fatter.
3. On the London Underground. Anywhere. Well, below ground.
Ok, so the point I'm trying to make is that coverage is much, much better than it used to be. I had an i-mate Pocket PC for a few years before my JASJAR and I've seen coverage improve over the whole country for the last 5 years. But even then, it's never been that bad and even if one or two syncs missed, the next one would generally pick it up.
Anyone who thinks they're having trouble with coverage really needs to consider getting another device because it just isn't that bad. I feel badly off nowadays if my 3G drops back to GPRS.
I can't speak for Blackberry as I'm an avid Windows Mobile user, but...and let me think on this...no, other than Rowen I can't think of the last time I had trouble with coverage at all. Maybe my device missed a sync or two. But I just never noticed.
PDAs were pretty boring and fairly redundant before they had phones built in. Converged devices (if that's what we're calling them this month) is what mobile is all about.
PS. I don't have an iPod either and I like to listen on the move, but that's another story.