AmigaMance, may I ask if you have reported your experiences to Bernd? This is surely the most efficient solution to correcting bugs. AfA OS has come on in leaps and bounds since the initial versions last year, however as you suggest, the last two updates do not appear to have resolved issues that are relevant to your situation. It does not hurt to try however!
I am curious as to what kind of slow-downs you are experiencing. I spent a little while testing the speed of opening images using multiview with and without the AfA OS datatype library and could not detect a (noticeable) performance loss. Note however, that I am using WinUAE so the speed of 68k functions is difficult to measure.
Cheers,
James