It's possible you'll need to use a different developer to get results like you're used to with APX100, when using non-Agfa films. It might be that a different film-developer combination might give you results more to your liking than you're getting with whatever developer you're using now.

I have a great fondness for APX100, Plus-X and FP4 Plus all, but only one is still with us so it's obvious which one I shoot. I develop mine in PMK 1:2:100.

Have you tried Neopan SS? It's ISO 100 also. I'm not sure of its production future, though.