I pulled the Live+Installation DVD (hey, T-DSL 3000 rules!) and must say, I'm really surprised. Okay, there are a few issues: the keyboard layout is suggested as the default for the PC - but a Mac notebook can have different layouts (externally a PC keyboard, but internally always a Mac keyboard), so the selection should be a bit more clever. If you switch to the Macintosh keyboard in the selection, special characters like the pipe symbol and curly and square brackets and AT and such no longer work - with PC allocation, however, the labeling of the Mac keyboard does not match. And there is no allocation for the Mac special characters.
What also doesn't work is the second monitor - it is simply not detected and activated, not even initialized. Too bad, because Macs do have multi-monitor support by default, at least the PowerBooks and PowerMac models (the iBooks and iMacs only partially and then only with hacks). That should also be included in my opinion.
But otherwise - nice thing. That WLAN is not recognized is normal - or it is recognized, but not usable. Apple's WLAN chips are often not supported there. I also don't know where Bluetooth is configured - I probably need to install packages first. But that could also be done automatically in my opinion if a Bluetooth adapter is detected. Nevertheless, Ubuntu seems quite nice overall - it starts with usable defaults and already supports a lot of the computer. And the extensive translation of at least menus and dialogs in Gnome is very pleasant.
And that a Debian architecture is working underneath is of course particularly dear to me.
However, it is catastrophic that in the Live CD it seems that no terminal can be started anywhere ...