Lewis, No halos here, nada, zip, none
Last year I came to the conclusion that APO's are all wannabe's. Wannabe reflectors, that is.
Shocking, I know.
They can be very good, I agree, but none are perfectly achromatic across the whole spectrum in the way that a good reflector or catadioptric is.
FWIW there is an interesting rumour that Questar is considering making a Q5. That should be a really, really interesting scope, and if it came down to a choice of that vs a Takahashi I'd take the Q5, no question.