Upgraded a MB and MBP today, here's some things you might find interesting, or not I guess.

The default install is an upgrade. To change to an Archive and Install or Erase and Install you need to click the customize button on the Install Summary page.

I sure wish the install windows would have been more clear on that point. There was no indication, none, that it was upgrading. I wanted to do an upgrade so all was well but that was a stressful 60 minutes staring at the window saying 'Installing..'.

Neither of my laptops see my Airport Extreme or Airport Express routers since upgrading to Leopard. They see the Linksys just fine. Aaaargh. A firmware update on the Extreme didn't help. Haven't mucked with the Express yet. I sure hope this is something wacky that's just affecting me.

Leopard disables any right-clicking preferences for mouse or touchpad. Easy enought to reset but wow, Steve REALLY doesn't want us right-clicking.

Leopard breaks PithHelmet in Safari. It was working on 3.0.3 in Tiger. There's no new version of PithHelmet yet. Grrrr.

My default user is a 'standard' user. It's best to log on as a user with admin rights at least once after upgrading. There may be a firmware update for ya. There was on both my laptops.

Leopard broke my Cisco VPN client. No big deal, just needed to uninstall it and install the new version.

Leopard didn't affect my Parallels or VMWare stuff.

I'm seeing a noticable quickness to Leopard, I guess it's all that core image goodness and parallel processing mojo. If your Mac is a bit sluggish after the upgrade it's probably just Spotlight indexing your hard drive for the first time. Depending on your stuff it may be a few minutes or an hour.

All in all, digging Leopard, except for the Airport problems but I'm still hoping they're just broke for me and won't affect all of you out there.

Anyway, FYI, HTH, and FWIW