Let's start by rephrasing the question to "which is better?". The short and easy answer is "1080p". Gearshift can produce your videos in 1080p, 720p, or any other resolution.
Technically, the resolution is the same for both 1080p and 1080i (both displaying 1920x1080 pixels on the screen). The difference is the "p" and "i". The "p" is for "progressive" scan meaning each picture is painted top to bottom in one scan. The "i" stands for "interlaced" scan; these pictures are painted sequentially which means that odd numbered lines are painted first then even numbered lines second, making this a two step process.
Progressive scan is preferred because its one step process (able to paint the picture quicker than interlaced) produces smoother motion, particularly for fast paced action such as sports (OK, just the ones that make you sweat). Because of its longer processing time, interlaced scans can lag behind the data its receiving and cause the picture to appear blurry. High definition television broadcasts are in 1080i or 720p (progressive scan of 1280x720 pixels). The company will usually broadcast fast paced sports in 720p and slower content in 1080i. If you thought you've noticed a difference between sports and a sitcom, you could be right. They may have been broadcast in different resolutions.
In reality, 1080p stands alone. 1080i is more comparable to 720p. Manufacturers market their products as 1080i/720p (notice the "slash"). This means that the TV is "capable" of receiving 1080i signals but converts it to 720p, so try not to fall for this gimmick. Get started on your videos by contacting us toll free at 877-477-STUDIO for a consultation, and be sure to order a copy of our free Video Marketing DVD today.
Works Cited:
http://reviews.cnet.com/720p-vs-1080p-hdtv/
http://www.wisegeek.com/what-is-the-difference-between-a-1080p-and-1080i-hdtv.htm