The new version has a totally revamped networking stack that should be a lot faster and more reliable. Part of it includes a new UDP holepunching algorithm that's had a super high success rate for us in practice.

There are some diagrams describing this on the Hypercore Protocol [0] site, and the repo's can be found here.

[0] https://hypercore-protocol.org/#hyperswarm

[1] https://github.com/hyperswarm/hyperswarm