It seems there are things that the Solids++ fillet can do that the ACIS can't. Will it be sticking around?
Solids ++:
ACIS (will not calculate):
Even doing the edges separately with ACIS does not result in correct fillet.
Also not sure if you just aren't supposed to select a surface to fillet, but with ACIS it leaves a visual gap when do so:
Result:

|