It's a terrible OS for non-SSD users. I set up a $2000 iMac for my dad a few months ago, and it's slow as molasses in Winter.
It's an inconsistent and buggy OS. Things that worked in Tiger are broken, while things that came over from iOS seem to work. Multi-monitor support still isn't great, and if you don't mind me comparing it to 10.3, which was "lickable" like a lollipop, this is "lickable" like a flagpole in the winter.
Non-SSD users seem to be a mixed bag. What was acceptable for me is atrocious for others... Seems to be alot of differentiation between performance on similar systems and usage patterns.