A 1080p YouTube trailer played smoothly in my office, but was a bit laggy with a lesser Wi-Fi signal in my house; an offline MP4 of the trailer looked great in either location.
The Kangaroo can output at up to a 4K resolution via its HDMI port, but when I attached this desktop to an ultra-HD monitor, the system seemed laggy during all tasks and was unable to play a 4K MP4 video. I was also able to power two monitors at once by connecting the Kangaroo to a DisplayLink dock, but the system became laggy after I opened just a few tabs. Kangaroo recommends that you not run at resolutions higher than 1920 x 1080, though the slightly higher resolution of 1920 x 1200 provided good performance in my tests.