Also have the latest 10A222 build on my MacBook, but as an everyday OS, it's still too unstable. Quicktime will just randomly crash and shut down, even with 4GB of RAM, I will get consistent slowdowns. But, this is a developer preview, and for one, it's pretty damn good.
I was stunned that the install time was only 10 minutes on my MacBook 2.0(About 20 minutes on a Mac mini, but with all the printer drivers installed). The overall footprint of Snow Leopard is a lot smaller as well, with nearly all built in apps just a fraction of the size as their predecessor.
I haven't noticed a significant increase in performance, but again, it's a developer preview. The only thing I have noticed, is that Safari 4 will turn on fast. I mean
fast. Right from booting Snow Leopard, it's just 1 quick bounce before Apple.com has loaded up.
It seems to have much promise and some excellent features, but as a Developer Preview, I wouldn't recommend it as your main operating system.