I had judged against a WO 66SD and found the 60 mm Asahi-Pentax to be the better scope.
I'm curious as to "how" it was "the better". Correction? CA? SA? Baffles? Focuser? Build quality? Usability? Fitness for purpose?
Normally you'd expect a "little" APO to wax an achromat. And since it's much shorter the moment arm on the mount, you'd expect it to be more solid on any mount. But an inexpensive manufactured item might lack in quality.
I remember when the early Nikon APO's came out, they were f/12 - not much different in focal length than the f/15 achromat's they were replacing. There was a substantial improvement with all three of RGB coming to the same focus.
I'd expect that any APO would do the same. Perhaps ... they didn't all come to the same focus?
Edited by wfj, 21 July 2018 - 05:03 PM.