There's a lot I like about Apple's sense of design, when it comes to both software and hardware. They seem willing do adopt some good ideas from the outside (Leopard finally has multiple desktops), and include lots of things that I've not seen elsewhere (I like the side-buttons on the Mighty Mouse, and the way they let two fingers control a touch screen).
However, as someone who switches back and forth between more standard unix systems (OpenBSD and linux) and Mac OS, I initially had some gripes. I can switch between the user interfaces easily enough, but Apple keeps "improving" certain administration tasks in incompatible ways that really annoy me (though after taking some time to calm down, and find some factors that reduce the level of annoyance, these are not enough to make me return my new Mac that came with 10.5; after a few more days, I am now quite happy to have updated).
As recently as 4 months ago (June 2008), Apple referred to support for the Unix File System. However, the Disk Utility application does not offer it as a format (at least, not when partitioning the internal disk before installing), and when I start "terminal" and use the command-line "diskutil partitionDisk..." option, I get errors when I try to create a UFS partition.
Now that there is a case-sensitive option for HFS+, my first reason for choosing UFS is gone. The other (ability to use "tar" to create backups that I can put on any Unix system while preserving user and group id information) may also be o.k. now, according to what I've been reading: tar and other command-line utilities now reportedly hold onto the resource forks too (though they aren't useful on non-MacOS systems, they can be re-constituted on another MacOS file system, and the data forks that constitute all the important content of other files can be read on other flavors of Un*x.).
On the topic of file systems, I was able to create a ZFS partition with diskutil (after reading about command-line partitioning on Apple's document Mac OS X Server Command-Line Administration For Version 10.5 Leopard. The partition doesn't seem to mount automatically at boot, but perhaps I can mount it with diskutil...
My recollection is that, for a while, Mac OS X was doing uid/gid's in what I consider "the right way", i.e. every time you create a user they get their own group id too, and then you can just set your umask to 002, and give files some other group ownership any time you wanted to share them. (Yep -- a quick check of a 10.3 system confirms it creates a new gid for the new user I created.) I did this manually for a while on non-MacOS systems, and now Ubuntu seems to do it by default, but when I just created some accounts on a new Leopard machine, they all seem to come up with gid=20.
It seems that it will, at least, be easier to fix things, as one can get to uid/gid information by right-clicking on the user in System Preferences rather than having to launch Netinfo Manager. Once one looks in "help" and finds that there is an option to create groups in the "Accounts" dialog, this is actually a smoother interface than 10.3 had, though best of all would be the nice interface with the ability to create a new group with each new user...
According to Apple, there is some trouble joining a wireless network with hidden SSID (a "closed network"). My machine seems to go on and off the network just fine (using WPA2 personal as the security protocol), and let me connect to the outside world beyond my home network, but when I try to connect within my network, it can't look up other machines (by name or, if memory is correct, even by IP number). For example, when I try to use the finder to "Connect to server" to get to a file server on another system, no systems are listed, and if I type the machine name, it is not found.
The simplest fix for this would be to just un-hide the network ... but of course the AirPort Utility program can't find the network and thus can't configure it! Fortunately, I was able to connect to the base station by giving the IP address 10.0.1.1 and entering my password, and thus re-configure the base station to not hide the network, and will now reboot all machines and make sure this worked! (Yep, I can now connect just fine with ssh and Finder.)
With any luck they will fix this; for now, I'm hoping that the regular security plus registering MAC addresses will be enough.
I find it really annoying that firewire disk drives unmount when nobody is logged in, so if you have a user's home folder on a firewire drive, that user can't connect via ssh. Perhaps there is some way to overcome this. I took a quick look at System Preferences, but haven't tried a google search yet.