I like your choice of words... "Linux still is". Yeah right, and will continue to be.
If you want Unix why not go FreeBSD or NetBSD?. FreeBSD and NetBSD, as far as I know, have both KDE and Gnome, both very mature and user-friendly desktop environments which have evolved and were perfected over the last 14+ years on all *x platforms (BSD, Linux, Solaris Unix), plus all the usual open source applicatons we´ve come to rely on: Firefox web browser, Thunderbird e-mail, OpenOffice, K3B for CD/DVD burning, VLC as media player, etc.
Plus it comes without the attached strings that hook you up to the Apple money-sucking machine.
Oh, wait, there´s more:
------ Mach, which Apple has adopted for Mac OS X, puts anything that accesses hardware into the microkernel. Under Mach's philosophy, XFree86 still shouldn't be a user process. (...). This arrangement is a good business argument for Apple funding mkLinux: all the drivers for their proprietary hardware, thus much of the code they funded, stays inside Mach, where it's covered by a more favorable (to them) license. ------ http://www.linuxjournal.com/article/6105
Or, you could also go "where the action is at" and run a bleeding-edge Linux like RedHat´s Fedora.
Or Ubuntu, for that matter, if you prefer the dumbed-down, hand-holding experience. There´s no shortage of scientific software on Linux... including Maple.
Just my $0.02 FC