I like Lisas a lot. They're strange and fun to hack on---they have a lot of complexity, but virtually all of the parts are through-hole, and most ICs are off-the-shelf 74-series logic. You can understand the computer at a very detailed level if you choose to. Also, compared to its contemporaries, there's a whole lot of computer there for you to understand: a strange homemade MMU, a disk controller powered by its own 650x chip, a video system that can draw pixels from anywhere in RAM, a highly-engineered operating system with all kinds of workstation-like features, funky bespoke hard drives with a funky bespoke protocol, and more. (All the docs on Bitsavers really help you dive deep.)
Seeing right into the guts of how all of these things work beats staring and some mysterious black VLSI square on a modern motherboard. There's not much you can understand about those without signing an NDA, and even then, what would be the point? (Counterargument: those folks who made the amazing
Previous NeXT emulator have delved pretty deeply into that platform's mystery chips, so anything's possible, but you have to be much more talented than I am!)
Anyway, you are largely making your own fun when you start working on Apple Lisa projects. There is just not really much software, so unless you want to build it yourself like
some kind of weirdo, you're limited to a software library that was innovative in some ways for its time but is otherwise pretty dry today. If writing your own code floats your boat, though, then great! There's a whole lot that people haven't really done yet, so far as I know (insert tangent here about making new Office System apps with the ToolKit).
So I don't agree with
@Gorgonops: even if it weren't a technical milestone, it'd still be fun and interesting for the hacking pleasure. Everything is similar enough to the systems that "made it", but just different enough to be odd and interesting.
But if you don't like spending an evening poring over ROM listings, for example, then yes,[SIZE=1.4rem] a Lisa is a bit of a museum piece[/SIZE][SIZE=1.4rem] (and a heavy one, too!).[/SIZE]