There's a significant amount of selection bias gong on at these forums: it's understandable that we hear a lot from guys like landtuna and Dave who have problems with DTV reception, but relatively little from those of us who've had good DTV experiences. Happy viewers don't complain, after all. (And on the professional level, the work we put into DTV education at WXXI in Rochester seems to have paid off: the vast majority of our OTA viewers have managed to keep getting our signals, and anecdotally we're hearing about an increasing number of them ditching cable, especially given that we can now offer them three channels of programming instead of one.)
My personal experiences here at home in Rochester have been very good as well. Like many Rochester viewers, I'm so close to the local TV tower farm (less than a mile) that analog reception was always questionable here - plenty of RF, but gobs of multipath along with it. Once I figured out how to sufficiently attenuate the signals reaching my TVs, I've replaced five ghosty analog signals with ten solid, clean digital signals, including over-the-air CW that we didn't get in the analog era. (My upstate NY neighbors in places like Elmira and Watertown have done even better in the digital era, getting local OTA CBS, Fox, PBS and CW service they didn't enjoy in the analog years.)
I travel a lot, and aircheck local TV as I go, and so I've had the chance to watch local DTV signals all over the country in the last few years. There are certainly problem spots out there - the combination of VHF signals and the Las Vegas Strip comes to mind as a particularly bad one, and the Vs in Los Angeles are pretty rough, too - but I have a big pile of DVDs here that will testify that in most parts of the country where I've been traveling, the combination of a decent antenna (I travel with the Terk HDTVi) and a decent receiver yields pictures that are of a much higher quality than my traveling OTA reception in the analog days - or of the hotel cable, which I now largely ignore as I travel. (There are exceptions, of course: I spent a night in Winslow, Arizona this past spring, and without cable there'd be no TV there at all; on the flipside, I was in Santa Fe, NM a few nights before that, and was watching nice solid pictures from even the LPTVs on Albuquerque's Sandia Crest, 60 miles away.)
And for those of us willing (and able) to bother with external antennas, DTV has been a boon in another way: I could always see most of the Buffalo (65 miles west) and Syracuse (70 miles east) signals from here in Rochester, but only through a haze of snow and ignition noise. With DTV and the move to UHF, those signals aren't always in 100%, but when they are (90-95% for most of them), they provide clear HD pictures that make a nice alternative to my local affiliates when they're preempting network fare.
None of this is meant to minimize the very real problems that some viewers are having with reception...just to point out that there are lots of other DTV stories out there that don't get discussed much on these forums.