0.5-1.0
Just didn't do it for me. A 0.5 was a waste of time, a 1.0 was decent enough for a single listen.
1.5-2.0
I liked this, although my liking wasn't enthusiastic. Definitely worth a few spins.
2.5-3.0
I liked this release a lot. Good for a handful of listens.
3.5-4.0
I loved this release. Worth many listens. It'll probably end up as one of my favourite releases of its year.
4.5-5.0
I love this release so much that I'll never stop listening to it. Worth endless listening.

I only rate stuff I've listened to recently, so not everything I like is actually rated yet, including quite a few 4.5s.