First off, outside of the very few CRT based sets left and a couple plasmas, there are no more "1080i" sets made. This doesn't mean there are no sets that will accept a 1080i source, it just means there are no native 1080i sets. 95% of the sets bought today are fixed pixel 720p or 1080p. All will accept 1080i signals and scale/deinterlace to their native resolution. So your choice is between 720p and 1080p.
So, on to 1080i/1080p sources. Although some older 1080p sets deinterlace 1080i signals by taking the 540 lines for each frame and doubling them, most newer sets deinterlace by taking both 540 line frames and weaving them together to form the 1080p frame. This means no data is lost or doubled and the 1080p picture loses no quality, it is just displayed differently. If you have one of these 1080p TV's that does a good job at deinterlacing, then a 1080i source should look just as good as a 1080p source.
In most cases, the "Full HD" stickers you see are just a marketing ploy when it comes to HD sources. No broadcast source is available in 1080p and the only thing the "Full HD" thing did for HD disks is give the unknowledgable a dumb marketing term with which to criticize the 1080i players released by one side in the HD format war. I own(ed) both a 1080p Blu and a 1080i A2 HD DVD player and the pictures were identical.
So to sum it up: If you are sitting close enough to the display to reap the benefits of 1080p, then a 1080p set is a benefit since it allows a bigger picture with more resolution (see chart below). If you aren't going to be sitting close enough, you won't be able to tell the difference between 1080p and 720p. As far as source material goes, if you have a newer 1080p TV, the difference between a 1080i and a 1080p source is very minor if it exists at all.
[/quote]
