They've still got a way to go, but considering the short life span of the project, it has advanced leaps and bounds, but alas...
Short life span? hey've been working on it for over a decade!
Alphas are not something that you want to use as your ALT OS. Time will prove Haiku to be the best. 
I've seen release OSs that are less stable!
I had it on a netbook a couple of years back and it was fairly stable and very quick given the low end hardware it was on. I know some of the developers were using it as desktops even and I'd imagine it's improved since then.
