OK so answer these comparative questions about your EDTV:
1. What make & model / diag size?
I recommend any of the panasonic edvts, 37 or 42 inch, or the 42 inch zenith/lg edtv panel, these seem to have the highest praise. If you want a larger screen, hdtv whether plasma or some other technology is the better choice since it needs to be bigger to really be true hd anyway.
2. What was the retail cost?
I bought a zenith/LG electronics 42 inch edtv on clearance at best buy for 1150 a while ago, generally though there is a significant difference between the prices for edtv and hdtv, but you still need to look for a good deal. And remember the model is everything, don't get a cheap edtv or hdtv.
3. What resolutions will it display?
EDTVs display 480p natively. But they also have scalers built in to display all current hd resolutions that a typical hd model would. Higher resolutions will look noticeably better than 480 and standard tv on edtv models even though its not truely displaying all the detail an hdtv set would. You can choose any resolution you want from the source, if available and it will display fine on an edtv.
4. When you try to view a 720p or 1080i source from cable, 4DTV, DBS what resolution are you displaying?
That's a matter of debate, many contend it's still 480 on an edtv set no matter what you are trying to display, but again, the image looks noticeably more detailed with higher resolutions with edtv scaling, albeit not as good as it would look on a true hd set.
And a general question: How is 720P or 1080I on "SLIGHTLY IMPROVED" over 480P?
That's not exactly what I meant to say. 720 or 1080 is a large improvement over 480 on any set, but when you factor in the ability for an edtv to scale these resolutions, the difference is not as great. You probably see a bigger jump on hdtv sets from 720 to 1080 on hdtvs than edtvs, though both look somewhat better on hdtvs particularly from within 6 or so feet.