I've been playing for a while with both systems, cause I can use any of both, I have an NTSC console and TV has built in NTSC(usa) and PAL-B(europe).
About the black bars at sides, in NTSC for 4:3 movies comes from that std aspect ratio for NTSC interlaced is 640*448 instead 640*480, so if you have any movie in 640*448 you can check in older versions that fits in full screen.
Using 640*480, the rectangle is something like 16:9 movies that you have black bars at top and bottom but in this case cause height is more than std, image was cropped at sides.
Making history first fix was expanding image in width for NTSC fix, but that crops a little other aspect ratios 16:9 and 20:9 for example, getting some kind of pan-zoom for those, so fix something but another thing has to be fixed. After all the solution comes and is posible to see 640*480 as 4:3= 1.333 instead 1.42 and 640*448 are seen in the same way. The result, no more black bars at sides.
About resolution, NTSC is worse than PAL, that was ALWAYS...PAL has 625 lines and NTSC has 525, so that is system intrinsec. I can watch movies in better quality using PAL than NTSC, and I think there is nothing to be than about. Also with DVD same thing happens.
Due to that is possible to see horizontal lines more in NTSC than PAL, and are more noticeable in non-interlaced mode, and more as bigger is the TV set.