I announced a 5.0 pre-release candidate over a week ago -- in fact, I announced a few over the past week as I was inspired (and had the time) to code some additional features. I didn't expect more than just a few people to see, and then download / test, the pre-releases.
This morning I spent a few hours looking at, fixing, and then testing some minor bugs. I made the DEV versions available as I went, so people could fix their issues quickly.
It's always difficult to hang on to updates while there exists an issue in the stable version. This morning I released 5.0.1 quickly because I will not have time later today.
I don't (yet) have a group of beta/pre-release testers, but that's certainly something I'd like to setup. I may even offer "bug bounties" on the pre-release versions. ;-)
Thanks for your comment - I always appreciate feedback to help improve my work.