I was one of the nerds that went to church, er, the Apple Store, yesterday to pick up Snow Leopard, the OS X update. For $29, I think it's a pretty reasonable upgrade price (are you listening, Windows 7 pricing people?), considering it's an evolutionary upgrade and not feature heavy.
The first win was getting back 10 gigs of space from my hard drive. I thought it was supposed to be only 7, but I'll take what I can get. My Mac Pro's system drive is also where I put my iTunes library, and it's getting crowded.
Booting and shut down is faster, as they said it would be. Time Machine backups are crazy fast now, where it used to be that the icon would swirl for ages without anything new to even backup. Everything in Finder seems snappier, though it's hard to quantify it. The slider in Finder windows for icon size is a welcome addition. Spotlight seems faster. Stack navigation out of the dock is far, far better now that it scrolls.
I wonder if they haven't tweaked memory management. Parallels seems to be more responsive when I've also got Photoshop and/or Aperture open. Perhaps it's the CPU core management. It's all that under the hood stuff that's hard to measure.
Lots of little tweaks that I've read about, but not encountered, are intriguing. That it can figure out what time zone I'm in and adjust the clock is really cool. Definitely a worthy and inexpensive upgrade. And did I mention there are no install keys or other such nonsense?
I appreciated that whatever it needed to download, it did during the install. Unlike Windows, my first step after install wasn't going to http://macupdate.mac.com :)