Yeah, Vimeo is pretty much rubbish these days, with their adaptive streaming.
For about a year though Ive been using these guys, they're the only site, it seems, that actually allow you to force HD. When I share a video, I steer well clear of Vimeo and always go to Iplayer. The quality is superb compared to YouTube and Vimeo.
I pay for membership, but they're doing first year free for newbies. I can't recommend them enough to be honest.
Here's some footage I shot on an old RED Scarlet
http://iplayerhd.com/player/video/57a4b81c-47b3-4c87-afd7-6c7f877bf6a7/share