Wow, that’s a bizarre article. It seems to be arguing that because there’s more than one HDTV standard, there’s no such thing as HDTV, and even if there is, it doesn’t look any better than non-HDTV.
It even sounds plausible at times, as long as you’ve never actually seen the difference for yourself.
I remember when we were looking for our first flat-screen TV we went to Best Buy (only because of they had different types) - we saw the LCD, Plasma, that ‘mirror’s’ thing (said it had millions of tiny mirrors for whatever reason). We settled on the LCD. It’s bright, great color and least expensive. The Plasma looked ‘smeary’ in that the colors seemed to be humid (???) damp, not very sharp.
720P is better then 1080i, several TV stations broadcast on 720P, 1080P is mostly limited to BluRay discs, but some “may offer” 1080P like DISH, but it is limited and at a “premium”.
Below is a few years old:
http://www.hometheaterhifi.com/technical-articles/155-high-definition-1080p-tv-why-you-should-be-concerned.html