I need to do a big project and I don't have a 1080p tv to test the highest res. Is there a big difference in the two modes (quality) because shooting in native mode is nice for the space! The project will be exported in HD on a blu-ray disc.
There is a modest difference. If space is at a premium, stick with 720/24pN. If you're greenscreening or you just want the absolute best quality, go with 1080/24pA.