Have to say that it does seem time to try a "higher quality" frame, just to see the difference. An 80s Trek or decent Nishiki (or the like) could provide an interesting comparison for under $100 and a day's labor switching the parts. On the other hand it seems like you are into the fact that you have made a great rider out of a frame most would pass on, and I respect that. Given that every Surly is straight gauge 4130 (not much different than your tubes?), who's to say?
I think you will get a lot of people who will support your right to ride and enjoy any bike you want, but I doubt you can convince people that these are somehow "overlooked" quality frames. There are just too many Japanese-made double-butted steel bikes out there to seriously argue about quality.
I'm one who says enjoy what you like but don't overlook the joy of riding something different! Or, if you enjoyed building and riding this bike, why not another?