If speaker is great AND the output transformer is great, it should sound great. We'll see. Essentially it's a small
power amp, a speaker and an enclosure. The only piece out of the three that's cumbersome to make by yourself is the enclosure, everything else is easy and pretty inexpensive. And judging by the tubes and the lack of tone controls the design is pretty much classic, i.e. the one you can find in any other
tube power amp out there. Why the heck did they have to hire an engineer for that I don't know, it's in every textbook.