The videos are low quality even when uncompressed - believe me, a good codec is used - but if the source isn't HD, the codec is not going to make them look HD. The bandwidth and storage limits are such that the videos are designed to give a taste of what the displays are like - but they're no substitute for being in Montreal - hopefully people will be attracted to come in person.
The organizers of the competition do video the displays in a higher quality format than the videos shown here - but for various complex reasons they cannot be made available to the public directly.
If you want to communicate directly with anyone who has made a video, go ahead - but I don't think there are too many people who actually go to La Ronde who have videos available.
As for feuerwerk.net, I believe their videos are available for sale - there's a difference between what you can get for free and what you can get for money
Paul.