Performance wise, there probably isn't a lot of difference between them. The Orion has much more of a recurve riser (though A&H is now making a recurve riser or two as well. I tend to like small risers and own several ACSs. They do everything I want them to do.
I have one observation about risers that are made to accept both recurve and longbow limbs. Most such risers, including ILF risers, are designed primarily for recurve limbs and have a more obtuse limb pad angle. Works well for recurve limbs, but robs just a little performance from the longbow limbs, which would benefit from a more acute limb pad angle, developing more early load as a result.
The standard A&H riser has an acute limb pad angle designed for longbow limbs. I haven't seen an Orion riser up close, so don't know it's relative limp pad angle. Can change the pad angle on an ILF bow, of course, by cranking the limbs down, but that's still not usually enough to get the best performance out of longbow limbs, IMO. Not everyone would agree with me on this point, of course.