yes, aftertouch can be useful
Synth keyboards take pretty good pressure for Aftertouch, and it
doesn't feel weird and works pretty well, but the Roland Accordion
aftertouch has a feel like it bottoms, then slips a cog to get to aftertouch,
and it doesn't take much to slip past the "spot" and then the physical distance
to the true bottom of key travel is quite noticeably different
the fr3 and 4 are nice as MIDI controllers, but there is one more "gotcha"
in that bellows control midi messages are a rather incredibly dense stream
of data, and sometimes we need to adjust data output settings so as not to
overload what you are talking to
good luck with the tryout.. turn the volume up higher than you think it should be
at first so you avoid the stiff-bellows sore arm (until you get used to it)
and have some fun !