I flew the Knight Pro this morning for the first time since before Christmas (I have been flying the Knight 3D and other things in the interim).
After a year and a half (with some sitting) and eight or nine gallons through it, I have had to replace the balls and ball links on the tail pushrods, changed the clunk line, and now find that it needs a new left, lower canopy grommet, and stickers.
It does not wear out (so far) and still appears to be in very good shape.
The only mod done to it was changing the Bell/Hiller ratio as outlined on Aide Law' "Flying Aid" website.
It feels much slower than the 3D, which is to be expected, but is still pleasant and predicatable to fly.
I realize it probably was no longer a "hot" seller, but it sure flies nice. Too bad it was discontinued.