ScheposNbox/FollowingBob have a active solution too....fits the classic Schleps type stereo bars...more expensive than the Naiant solution...but Naiant is not currently taking orders as far as I know
Correct.
To give an example, the Naiant Active PFA's with a 5' cable and 10' extension was around $220 + shipping. When I asked Nick about the other option, I was quoted $600 shipped. The SchoepsNBox/FollowingBob actives are 20% lighter and about 1.25" smaller at the back end because of the binder on the Naiant's. I went with the Naiant solution because it'll do what I need it to do, and as you mentioned, Jon's "stopped" doing them for now (after Batch #3) so he can concentrate on other products so it kinda leaves the other option as the sole solution at this time.
I'm expecting the used caps to go for closer to $350 (maybe slightly more) now that there's an "increased" demand for them because of the actives. I know I had to buy my CK61's new but am keeping my eyes open for CK63's.