Regarding the valid concerns about unlimited data, I do have a question; In our wifi world, where about 90% of my time I have access to a wifi network, how Important is unlimited data via cell network anyways?
Not very important, until you go over. Then it's vital.
AT&T's 3 gigs are pretty easy to blow through if you decide to watch a few movies/TV shows while you're out and about. If you're a heavy e-mail user, with attachments, it's also not hard to get to those "we're adding $10 to your bill for another gig" messages.
Wifi bugs me for a couple of reasons.
First, if I'm paying beaucoup bucks for wireless data and other services, I expect coverage and availability when I need it. If I hang out on WiFi most of the time, there's no point in paying for service at all -- just use VOIP on a PDA! Or go for super-cheap 2G voice and text service and use only WiFi, and save $80 or so per month.
Second, there's no REAL reason to throttle and cut back data speeds (or worse, cap) other than sheer laziness on the part of the carriers. They're not adding sufficient backhaul. And consider on the flip side, when carriers sold people MUCH more than they needed... they tried selling my mom a crazy smartphone plan with "unlimited data" years ago for $180/month until I stepped in and screamed at the carrier rep. Nobody called her and said "you've only made 4 mins of calls, sent 15 texts and used no data." Yet once people started USING the "unlimited data" plans they were selling, oh it was bloody murder -- those horrible "data hogs" USING what they paid for!
Third, WiFi has security and access concerns. There are exploits to hijack and packet-sniff WiFi data, which could be used on public networks to grab confidential or sensitive information that's inadequately encrypted (including e-mails, even stuff like bank/credit card details). And if I had $1 for every time some public WiFi system decided that content (including this web site, as well as app updates) was "inappropriate" or "out of scope" or "blocked," I could afford an unlimited Verizon plan.
That's not to say I don't use WiFi -- I have 100 Mb/second service upstream and downstream at home, which is faster than any wireless carrier. But if I have to rely on or "look for" WiFi on a regular basis for any reason (coverage, data caps, etc.), I think that means I have the wrong provider.
T-Mo has been good for this city boy in that regard. Fast speeds, good connection quality, low prices, and uncapped service.