RE: brace height, riser or ATA
For real forgiveness it boils down to a combination of ATA and brace height. No one thing can do it all. But I personally find that ATA is more important. I have two Martin bows with identical cam setups. Mt SlayR is 37 3/4" long (long riser) with a 6 1/2" brace height. My ShadowCat SE is 32" with a 9 3/8" brace height. The SlayR is the more accurate of the two by far all things being equal.
All this being said I just ordered a new P3 Elite at 38" with an expected brace height of about 7 1/2" to 8". This should give me the best of both statistics and be more forgiving than either of the others. This will end up being a target/3D bow, giving up a little speed for more accuracy.