Without a dual-core processor to put some oomph behind it, the HTC Sensation XL is limited to 720p video recording rather than 1080p, but it does have one handy trick up its sleeve. You can record slow-motion video (at half speed) at a resolution of 800 x 480, which is a cool thing to have around.
The only problem is that the video quality on the Sensation XL is pretty much garbage, even at 720p. In the videos below you'll see that there is a huge amount of digital artefacting, to the point that you can see big squares in the videos where the detail has been lost.
Even in the slow-motion footage of the birds taking off, all they really are is white shapes – there's no detail or texture to them. The motion is smooth, sure, but then it damn well should be at half speed! At least video seems to handle contrast slightly better than the stills camera.
The culprit for the issues is an alarmingly low bitrate for the videos. The 720p video is recorded at just 5Mbps. We'd expect 8Mbps as a minimum for decent 720p video quality. There simply isn't enough data being recorded here for the video to be any good. We don't know why HTC has limited it so much – possibly to avoid filling the 9GB of storage too quickly – but it's really disappointing.