Personally I think the more internet friendly format is more compatible with YT. You might try the MainConcept AVC/AAC (MP4) & select the "Internet HD 720p." It's likely to be a larger file compared to the WMV format, I believe the compression is greater with the WMV. Also, after clicking "render as" scroll down & select "customize" then find the project tab & in the "Video rendering quality" area, change it to "best."
Another thing to try is recording & rendering in the 1080p in that same "best" way. The render will take longer of course, but it might make a difference after YT has taken down the quality, so that extra option of the 1080p is actually the 720p you originally intended to shoot for.
It's kind of the way people who wash clothing in hot water, use common sense & buy a larger size cotton shirt, knowing it will shrink to fit them perfectly.
Just for experimental purposes & common sense time management, I would do the test renders, on a VERY short clip, maybe 3 minutes long. This way, you find out the ideal end result that might take a few minutes, rather than an all day of rendering & uploading. Just render & title them "test clip 1 - 1080p best" & test clip 2 - 720 best mp4" etc.
One trick I discovered in creating a smaller file size without losing the quality. Is to first render the "project" that consists of multiple clips in the very best quality that takes forever. THEN open a new project, drop in that render in SV of ONE single clip you just rendered & RE-RENDER this single clip in that same best quality way. I've had a 2GB file size for a project I rendered in the best 1080p quality, (that took forEVER to render) down to 500MB doing this. When I viewed both vid's side by side, they looked exactly the same in quality, with one size at the 2GB & the other at the 500MB. It's a method I've found to be fabulous little trick.
