It appears to me that NBC in Miami has significantly increased their digital TV signal strength in the past 24 hours. I can now receive TV reception from a room that faces West or at Biscayne Bay. Before today, I was not able to get any NBC digital TV signal (stations 6-1, 6-2, 6-3). It's coming in nearly crystal clear on an analog TV with a digital TV converter box and only a standard VHF antenna. I returned the special digital TV UHF antenna a few months ago because it didn't help much. I also tested it earlier this week and I didn't notice any change. I am also receiving DTV 4-1 (CBS) and DTV 29-1 (Fox) DTV 29-2 without any significant transmission issues.
I guess the "beta" program is now over for Digital TV. I might eventually look at buying a HD Digital TV antenna for the living room. I'm not a big fan of my Satellite TV provider, but I'll certainly wait because in my opinion, their beta program really started this morning.
For other info on my experiences installing a converter box.