[TillE]

> and playing smoothly while the rest of the video loads, which Vimeo can't seem to do

I've always had at least sporadic problems with YouTube's buffering, especially at 1080p. I have a very reliable 50Mbit connection, but often I find that YouTube can't stream fast enough.

Usually it's only with certain videos; popular videos always buffer very quickly, which makes me think it's something to do with how they tune their CDN.

[jrockway]

You have a 50Mbps connection to your ISP. Your ISP may not have a 50Mbps * (number of subscribers) connection to the Internet.