I've been using an Apple MacBook Pro for a little over a year now, and I'm pretty happy with it.
There's a new update coming to version 10.5.2, which according to a release note available to Apple developers includes a raft of bug fixes, but I wanted to upgrade to Microsoft Office for Mac 2008 as soon as possible, so I figured I'd just go ahead and upgrade OS X at the same time. (I'll probably post a review of Office 2008 sometime soon.)
The OS upgrade process appeared to go well, but when I tried to log in, Leopard said it wasn't able to access my home folder. I use Apple's FileVault security technology, which stores my home folder in a virtual disk image that is encrypted using the Advanced Encryption Standard (AES). FileVault protects my data if the machine is stolen, and I regard it as an indispensable feature of Mac OS X.
Unfortunately, Leopard wasn't happy with the disk image for my home folder, and simply refused to open it.
I wasn't expecting this problem, but I was prepared for it. I made a backup of the machine just before starting the upgrade, and I also maintain a secondary user account without FileVault in case of problems with the primary account. I logged into that other account and discovered on the Web that other people have seen exactly the same problem.
Apple published a tech note suggesting that this problem is related to passwords of 8 or more characters-- my passwords are all a lot longer than that, and so should yours be!-- but the complex procedure described in the note for solving the problem didn't help me.
Ultimately I had to delete and recreate my primary account then copy my files from the disk image into the new home folder. It turns out I'd have wanted to do this anyway, since Leopard introduces a new approach to FileVault that works better with Time Machine, Apple's new backup program.
Everything worked properly when I was done, but this was a slow, awkward procedure that most ordinary users would never have been able to handle. I just wish the Leopard installer had checked for this condition and done all the necessary work directly.
With Leopard running at last, I was able to get Office 2008 installed, and I'm slowly working through a number of small issues-- learning how to work around a minor bug in the new version of Apple's Mail program, upgrading some third-party software I use, etc.-- but generally I'm happy with the upgrade. Leopard seems a little faster overall, and Time Machine is great. It gives me a lot of confidence that my data is better protected against software and hardware failures.
I'm also making periodic complete backups in case I get bitten by any major new bugs in Leopard or Time Machine, but I don't expect anything like that.
I may have additional comments, especially after the 10.5.2 update... stay tuned!