That is the original, now discontinued one. OP link is to the updated version.

Link in the OP is 404ing for me.

That is the point of the post.

what were the differences?

popcorn-time vs. popcorn-team

Well, besides that obvious fact.

For those of us who have not been following it's development; were there any noted improvements of the new (now-missing) version over the original?

I haven't been super up to date with the code but yes. Lots of bugs and faster and better error handling in the newer versions. Improved for every week.