friends 1080p is far far better than 1080i.... 1080p is the international standard for HD... to distinguish 1080p from 1080i, the 1080 picture is called "Full HD"
unfortunately in india HD means 1080i.... but service providers like DirecTV and Dish networks (USA) use 1080p for their DTH service....
the difference between the two is very simple....
1080i - i for interlaced.... so the picture is transmitted as interlaced signals.. imagine your tv as a screen made of many small horizontal srtips, in 1080i first the odd strips are formed and then the even strips are formed thus making a complete picture.... in fast moving scenes 1080i could easily have pixels due to this interlacing technology...
1080p - p for progressive... means the strips are formed one by one in a progressive manner thus making the picture more smoother....
however in order to see a visible change in quality you need to have a big screen of atleast 42inches... in smaller TVs the interlacing cannot be clearly visible....
and in any case 1080i cannot be better than 1080p... anyone who understands the logic behind the "i" and "p" will agree to it....