I always use a trusty anime site for my video soak tests, as I find that youtube can be variable all by its own self.
PS - Kissanime.com, the bottom of the episode pages lets you choose resolution and mp4 or Flash to download. Use with Naked Browser and no default video player, and you can choose what you like. I tend to use MoboPlayer or MX Player, whichever is best from the usual updates. (In other words, sometimes an update hoses an app until the next update, so don't choose a hosed app that you know good devs like them will have fixed soon, just choose your alternate.)
Btw - while free, no piracy involved with that site (videos are hosted on Google and whitelisted for Chromecast), and many episodes in the catalog go to 1080p.
Whether or not you like anime, it's a clean site with a variety of reliable test sources.
If you run an ad blocker and try to play the embedded videos rather than pipe to another player, you're likely to get a video from Google asking you to respect that some programming is ad supported and please support them on that. As much as I complain about everything, I saw no reason to argue with that. And the ads appear outside the video frames on the web pages, not in the video streaming. Pretty fair if you ask me.
Last thing - even at HD, cartoons are not very high bandwidth. You get to exercise your broadband radio and all the other parts without beating up your router or others in the house wanting the network.
Hope this helps anyone wanting to try some video testing.
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