I've had Leopard up and running on four Macs for 24 hours now and I think I've seen enough to talk a little about it. I installed the shrink wrapped version (10.5 build 9A581) on a brand new iMac, an original MacBook, and a nine-month old MacBook Pro using the upgrade method. In all three cases the upgrade took around 90 minutes and went perfectly. (The installer checks the install DVD before installing and this took an additional half-hour or so on my iMac, but once the disc was verified I skipped that process on subsequent installs.)
Apple told me in my briefing Thursday that the default upgrade install should work fine, and it did. Leopard disabled the now incompatible Mail extensions (Spam Sieve, GPG, Mail Act-On) and left everything else intact. I had to re-enter my .Mac settings and resynch my data, but all my installed apps seem to work fine, including Photoshop and Lightroom. Normally I recommend at least the "Archive and Install" option, but in this case Leopard seems to handle the upgrade smoothly.
I did an Archive and Install on my production machine, the Mac Pro, just in case, but I probably didn't need to. My experience was very much the same. Despite the negative experiences some had had with the Betas, Leopard seems completely cooked. The install experience is flawless. The new look and feel is beautiful, and overall performance seems much snappier.
Now for a look at a few of the new features.
The new Finder is beautiful, fast, and functional. Coverflow makes a lot of sense for previewing your documents - I won't be able to go back to the old column view - and I like the new 3D dock so much that I actually moved mine back to the bottom of the screen from the more sensible left-hand side. But it's not just eye-candy. The Leaning-Tower-Of-Pisa Stacks folder display, as silly as it looks, make sense. Like the rest of Leopard the new finder feels very solid and polished with small changes that make a big difference in work flow.
I didn't think I'd use Spaces, but Apple has done it better than other workspace implementations and I'm actually liking it a lot. For example, you can attach programs to specific spaces; Safari always loads in Space 3 for me, Mail in space 4. That little difference means you spend no time organizing your workspaces. They organize themselves. And that slight difference makes it useful. It even works with VMWare in Full Screen mode - so one of my Spaces is full screen Vista.
Similarly the implementation of notes and tasks in Mail is so logical and seamless that I've found myself relying on it almost instantly. Notes automatically migrate to your IMAP server by the way - they're treated like message drafts - which is another nice touch.
Time Machine is a simplified backup for people who never backup. It's turned off by default but it's on the dock, and I suspect most people will want to turn it on. Keep in mind you'll need a second drive that has enough free space to copy everything on your system. Leopard clearly wants to dedicate an external hard drive to Time Machine - it even changes the icon to a Time Machine icon. Configuration is very limited. You can tell Time Machine to leave out drives or folders, but there's no wildcard ignore. Time Machine runs all the time in the background but it doesn't seem to slow the system at all.
Despite what Apple told me, Time Machine only seems to work on local disks. I couldn't get it to recognize a mounted NAS drive. But if you're at all sophisticated you'll probably prefer the flexibility of something like ChronoSync anyway. I'm using Time Machine on the iMac but will continue to use ChronoSync to backup to my NAS on the Mac Pro. I won't bother with Time Machine at all on the laptops. (Update: some commenters say it works if the NAS supports AFP - I've been using CIFS. I'll give it a try.)
Spotlight works with Time Machine, and is much much faster. I turned off Spotlight on Tiger and turned to Quicksilver instead. On Leopard I'm turning off Quicksilver and using Spotlight. It's that much better.
The Parental Controls offer per login site filtering, time limits, and controlled hours of use. I've already turned them on for my kids.
iChat looks amazing with high quality audio and video recording, plus desktop sharing, and playback of Keynote presentations. I think we'll be able to use it to produce an amazing net@nite - I'm playing with it this weekend and I'll keep you posted. I'm hoping it won't require a prohibitive amount of bandwidth.
Overall I have a few strong impressions of Leopard.
First, it's rock solid. The extra time Apple took developing this shows. It works right right out of the box.
Second, there are lots of little changes everywhere - subtle changes that accumulate to make a big difference in usability. For example, Spotlight now automatically selects the Top Hit during a search, so instead of hitting Command then Return to launch an app you just hit return. The new Help menu features a search box as the top item. You can search for a command in a program and it will open that menu and point to it. It's a small thing, but something you'll appreciate.
Leopard is not a revolutionary release - I wouldn't expect it to be, it's a mature operating system - but it is easily the best OS X ever, the culmination of a decade of UI research and OS refinement. It's elegant, fast, and eminently usable. Amazingly there are no showstoppers or major compatibility issues. I've only found a few tiny things I don't like - where's the Info Panel in iCal, for instance, and what happened to the nice transitions in Front Row - but I've been stumbling across dozens of little touches that just make me smile.
If you have an Intel Mac the Leopard upgrade is a must have.
(If you'd like to hear the new Leopard voice synthesizer reading this post press play here: Alex speaks.)