Solentbirder,
I was reading threads on the Audubon HHS and came across your old post about focus accommodation problems with the Pentax 8x43 SP. What you describe is the same problem Chhayanat and I experienced with the Nikon 10x42 LX.
Focus accommodation problems can arrise from the combination short FL (roofs generally have shorter FL than porros since the light path is straight through) and fast focusers among users who have presbyopia (age-related far sightedness, the eye lenses become less flexible).
Kimmo mentioned this on the Cloudy Days forum (the "day side" of Cloudy Nights). I'm not sure how old you are, but if you are middle aged, the problem may be as much with your eyes as with the binoculars.
Accordingly, the Audubon HHS, with its slower focuser might be a better choice for you.
I am wondering if you have tried the HHS or any other roof since selling the Pentax SP and if you experienced similar problems with other roofs?
Thanks, Brock