There is a reasonable difference between most films.
FP4+ is in a class of it's own, once you get to understand it with your system of exposure, developing and printing, it's beautiful, as you now know.
Neopan 400 is possibly the closest fast B&W film to FP4+.
I personally use FP4+ in 135 roll and 4x5" sheet film. With Neopan 400 as my fast film.
I develop all of my films in D76 1+1, which is a reasonably close developer to Xtol at the same dilution.
As for Acros, I have limited experience with it, about 15 or so rolls a couple of years ago. I found Ilford's Perceptol to be the best developer for me, for this film.
Mick.