I have 2 cameras my main is 1920x1080 .mts and my secondary which is blurry on fast movements is 1280x720 .mov both are 30fps (well one says 29.9 and the other says 30.0 in Vegas)

So I rendered my final product at 1920x1080 AVCHD .m2ts 29.9fps highest quality and I was expecting to loose some quality on the .mov files but not this much. Would .mp4 avchd gain more quality on my .mov files or would I sacrifice too much quality on my .mts files that way? Or is it the frame size should I downsize the entire thing to 720p? It's for youtube and vimeo