Could just be my browser, but it doesn't seem to play very nicely for me ( Firefox on debian jessie ).

First time I tried to hover, it didn't do anything at all, I think it might have still been loading ( or waiting to load the 'live' version until I hover over ).

When I got it to actually go 'live' they didn't seem smooth at all, stuff was jumping all over the place. Though, after watching them both fully, repeat playbacks seemed fine.

didn't get either of these issues in chrome on the same machine.