I promised a better Leopard bit, and here I shall deliver.

My install problems were caused by FileVault encryption, I’m very sure. Not that anyone else is upgrading anymore, but if you find yourself upgrading from Tiger to Leopard, turn off FileVault before doing the upgrade, and do a clean install just to be safe.

Now that I’ve been running Leopard for a few weeks, I’ve found it to be a large improvement over Tiger. Here’s why:

• Spaces. There’s some bugs to work out but it’s more comfortable than any of the Tiger virtual desktop things I tried. (Although still not as awesome as pretty much any window manager for X.) Especially when I’m just on the laptop, having the nice virtual desktops to sort out windows is a win.
• Finder not sucking. Again, coming from Linux, Finder is a step back from Nautilus or Konqueror. It can’t natively read SFTP or TLS/SSL protected FTP volumes. I’m fairly certain we still can’t write to FTP sites, which is atrocious (I haven’t tested this yet, actually.) However, some of the showstopper bugs have been fixed: Finder no longer hangs for five minutes if suddenly a network connection drops and a mounted network volume is no longer available, and the whole “mountiing a network volume” process has been streamlined and improved to the point where CMD+K is no longer the fastest way to do it.
• Consistent user interface. Again, it’s not Linux, so I can’t just arbitrarily swap out my GTK theme (or KWin or whatever), but Leopard at least makes all of the default apps look the same. I no longer cringe when I open up a Finder window and find brushed metal staring back at me.

Actually, that’s it. Finder’s not such a bear w/ regard to network volumes, and Spaces, and things look cool. Totally worth it for me, but that’s subjective.

As usual, however, TextMate, QuickSilver, and iGTD combined make OS X the most pleasing to use dev environment I’ve come across.