Fostex BK-16 Folded Horn Kit

I'm interested inbuilding this speaker kit from madisound. Looks interesting...single driver, no crossover, transmission line, $500...
I recently got a primaluna prologue 5 amp and sm thinking these speakers might be a fun second pair.

Any impressions on this speaker kit?
I heard these about 5 yrs. ago at an audio show being driven by tubes & I was impressed. Sounded full range to me in the small hotel room setup. I've always wanted to build a pair of these ever since.
It's nice but you may end up buying other drivers...Lowther, Merrill or ???

If you want fun, my Merrill Zigmahornets are great. Tiny footprint, amazing bass for a 4" driver too. Do a google search and you can find plans and reviews on 6moons.
I actually built these speakers a few years ago. I've been using them with an older NAD receiver and surprised at how good they sound. I'm sure they'd be a great match with a tube amp also.
Thanks for the replies! I think I'll eventually build a pair. They are pretty inexpensive and I'd like to try a full range, crossoverless transmission line just to see what they are like. Btw, those zigmahornets look pretty awesome, just too far beyond my woodworking skills...