Quote History Quoted:
Have a PSA 10.5" on the way. Will a Burris Fastfire III work on a riser? Have an extra and trying to plan before pistol arrives.
View Quote
I have a FFIII in the Burris AR mount on my 7.5". I like it a lot, but honestly, I like the PA mini RDS just as much and at 1/3 the cost for me, it wins easily.
That said, my 10.5 5.56 wears irons only, but I have been considering building another with a 1-6 strike eagle. For all around, I think I'd be very happy with that setup.
In the end, purpose and preference will determine the best option.
FFIII on 7.5 + KAK flashcan (for length reference)