The following by AppleSwitcher member Comandante was taken from the AppleSwitcher Mac Forum thread Hands-On-Leopard.

I’m going to look at this Pro migration path tomorrow from a web developer’s perspective: Coda, Firefox 2.0.0.8 w/ extensions, Parallels w/ XP, BBEdit etc.

As with any upgrade, take caution if you use your Mac for a living. I’ve installed 10.5 on an external drive, and will use that as a sandbox to test the applications I depend on.

I have installed 10.5 Leopard in my G5 Quad backup. So far I see a number of improvements and some minor slowdowns (Disk Utility takes longer to repair disk permissions, for instance). The Network control pane is vastly improved, allowing the setting of permissions of individual-designated users (a la AppleShare) for the first time. This is great news for schools and corporate outfits. Safari and Mail run much faster (actually like they were supposed to run since their creation), Spotlight runs orders of magnitudes faster doing searches but only after it has rebuilt its database, which could take, say up to an hour in a large hard drive (>400GB).

Printer SetUp Utility has disappeared from the Application/Utilities folder and is now located in the System Preferences as the control pane Print & Fax, as is Dock. Other new control panes include: Exposé & Spaces, Time Machine (a backup system-level system that I have not tried yet) and Widget Manager (allows to turn widgets on/off). Airport menu now shows locked (and thus unlocked visible networks) with a padlock next to the network SSID.

Warning: I have not tried to print to any of my three printers nor have I tried to use Aperture, Photoshop, Quark or any other elaborate environment that use calibrated ICC profiles for printing. This will come over the weekend when I can get round to futz with it.

So far the review is positive with the cautionary above.