i have NTSC cam, and i keep it in that format, although PAL is higher in resolution (576 horizontal lines) than NTSC (480 horizontal lines), while on the other hand NTSC has better frame rate 29 FPS, and if you convert it to 25 FPS PAL you will notice the difference, the same happens to resolution, 480 lines (NTSC) to 576 (PAL). When you convert from PAL to NTSC there are less losses in resolution but it is noticable since the frame rate is reduced. It is true that human eye cannot notice the difference between 25 and 29 fps, but surely the higher the frame rate, the smoother the picture