Gopro files workflow and export

Hi,
Im trying to make something nice out of the fairly nice clips from Hero 4, but my problem is export and uploads to YT.
No matter what settings or codecs, its all ending up real crappy on YT after upload, why?

If i shoot in 2.7k or 4k, and want to downscale it to 1080p, what is the best way to do so, in terms of min loss of quality?
What is your preferred export settings in Compressor?
My experience that Vimeo "allows" higher bitrates"

And another question i still havent found out 100%, when importing media as proxy/optimized files, will it not be exported automatically in normal quality later, or do i have to choose something to turn of proxy files before export?

I always export a Master File, then upload that to Vimeo, and let Vimeo's compression scheme to its thing. May take a tad longer, but I've always gotten great quality. Or just export an H.264 1080p and upload that.

When you have your Viewer menu set to Proxy, FCPX is only working with the Proxy files, period. Exporting will read from the Proxy files. If you want full quality, switch back to Original/Optimized and export.

Thanks, i wasnt able to reply yesterday since the site was down again, and no words about it... anyway.

I tried both master with H264 and Prores, Prores seemed to hold up slightly better, but im still far from satisfied.
Heres a short clip, what do you personally think, should be possible to achieve better than this too?
Masterfile is close to flawless here before upload to Vimeo.
vimeo.com/108737238

Regarding proxy files, you just unhook the settings in Preferences when done editing, or, is it another way to do it, not sure if it made any difference that way...

Like I said, the switch between proxy and original/optimized is now in the Viewer menu, top right of the Viewer.

What flaws are you seeing in that video clip? Looks fine to me.

Same here..the video looks good.