Most (85-90%) of current programming is still NTSC and I believe will be for the next 4-5 years. I will opt for a 4:3 ratio HD RPTV of sufficient width to provide me with a 16:9 HD image of equivalent size. The advantage? I will be viewing NTSC programming displayed full-screen at roughly 200-300% that of a 16:9 set.
Responding to Todd's observation that "no one in any store could tell me what the 16x9 enhanced mode was capable of..."
Consider this: If the sales person in a store can't (correctly) answer your technical questions, or at least find out for you, then you are probably in the wrong store. I would suggest that, for the purchase of something as complex as an RPTV or HD set, you stay away from the big box mass-retailers such as BB, CC and the ilk. And if you should later need technical assistance or service, you can pretty much forget about getting any from these guys.
From research to purchase, you will gain much more if you deal with some of the smaller (specialty) home theater dealers in your area. One of the local dealers in my area has been in business for 30 years. The first person to approach me on their showroom floor was the owner. When he realized I was a neophyte who was in the "research phase", he took considerable time to give me a pretty darn thorough overview of RPTV and HD as he demonstrated the features and capabilities of the models on display and readily answered my many questions. He also said they would match the lowest price I could find at any other retailer.
When I saw my first HD image (on a ~60" Pioneer Elite), it was a Kodak moment for me. I knew I had to have one of these things! But like a mountain lion waiting for the ideal moment to pounce upon its prey, I can be a patient guy. I shall defer my purchase of an HD RPTV until I - a) have acquired sufficient knowledge to make the best choice for my particular wants;
find, or negotiate my target price; 3) move into my new home.
For most of us who have made or want to make an informed purchase decision, HD is a challenging and complex technology. This is my wish for each us -- to be delighted to the point of awe with our individual choice of an HD display device.
But above all, remember "it's only TV". To quote Samuel L Jackson as he admonished Bruce Willis in 'Unbreakable', "Go to where people are; you won't have to look very long ...real life doesn't fit into little boxes...".