Hey!
I have been using Audio Note UK M1 Phono pre amp since 1997. If there were Audio Kit back than I might have bought their kit instead of factory model one. Anyway, I still have the M1.
As Audio Note UK. I've always enjoy their system at different shows I've attended. And their kit line are based on those finished products. So, I wouldn't hesitate to buy one if I ever in a market for a tubed pre or amp.
Compared to what out there I think it is a great value if you can swing a soldering iron. Those AN Kit amps looks greats. If those 300B interstage SET were out back than when I was looking for SET amps I might have bought them instead of my current amp... or maybe not, at least they would have been on my shopping list.
For the price of new Chinese made amp or pre amp, I rather built these AN Kit... well, if you can swing soldering iron and have time of course.

Take care,
Buddy