Anyone wanting to build that circuit should do a quick search, it has been much improved over the years, and there are even off the shelf PCBs that fit right in the case for cheap.

Personally, it is still cool. I think I have three or four of them in the house, and I have built countless CMoy-BB versions for my friends when they were selling the PCBs. It is pretty impressive, I still have one powering my very large Sony headphones right now.