The bad: he spent a lot of time making a simulation of a logic circuit that has no practical application I can imagine
It's probably a net plus overall, since learning and modeling what one knows is a great way to reinforce it, but one is left with the impression that this is a person who can spend a lot of time on things.
I hate to be a prude, and everybody loves a hobby, but we keep seeing these stories of guys who spend hundreds or thousands of hours on these very unusual and detailed configurations of virtual goods -- the maximized Sim City guy comes to mind. Something about our praising this behavior bugs me. I guess it's not clear to me the difference between unnaturally focusing in on small things - -like in Aspergers -- and just having a hobby. Aside from this guy, who seems wonderfully well-balanced, I wonder if we're not praising people who might actually need help.
I don't know. I probably didn't say that as well as I could.