I spent the past two days trying to get decent quality at 1080p YouTube output from Producer only to get unacceptable results. The captions had jagged edges. After lengthy discussion with Photodex, for now, it looks like uploading via Producer with 720p (best) will produce the best results.
Exchanging the initial Vignette Example tutorial file in 1080p video for a 720p (best) version resulted in a noticeably MUCH better caption display!
Compare captions in both versions at “full screen” view to see the difference.
720p (best) – Better video hands down
1080p – Captions are jagged around the edges.