So for keeping something in ipfs you need to have a server running ipfs seeding the files. You can use ipfs.js but it still needs to connect to an IPFS server. Webtorrent don't require any server running. All you need is the webtorrent.js file. That said you can still use a third party service like Infura for putting files in IPFS without running your own server. But Infura discards the file after seeding it for like 2 weeks. So you are not in total control of the file. In webtorrent you don't need any third party service. All you need is a browser with the webtorrent.js file. At the same time it is reccomended to run a STUN server to increase the reach of the files seeded by your webtorrent application. If you are creating a webtorrent application without a STUN server chances are that a lot of people would not be able to connect to it. I think IPFS on the other hand don't have this issue. Once a file is uploaded and is seeded by atleast one server it should be accessible to everyone else. (I am not 100% sure about this though). So choose wisely.

Well - and dat - and perhaps secure scuttlebutt, right?

This is built with WebRTC - so it uses the browser's native peer-to-peer API. But these other protocols also have WebRTC libraries, so it kind of all washes out. I only know dat really well, so I'm not an expert on all of this yet - but I'd say that the choice of protocol is less important than the maturity of the software.

For me, I was drawn to dat because of its incredible wealth of libraries (and the sweet Beaker Browser) - but if you're just serving video over WebRTC, you'd need to jump in and see how each library works for your specific project. In my mind, these are all really great projects.