Yes, the PA3X keys are semi-weighted. I wish they were lighter. Eventually I may HAVE to change to something lighter but for now I can live with it. Them seem very similar to T4, Audya, G70, etc.
I'm sure there are some differences that piano players might feel, but not so much for me, as best I recall about the others.
DonM
Since you are obviously pleased with the PA3x (and who wouldn't be) have you considered the PA-900? It weighs only about 24 lbs and even has speakers.
Perhaps Dave could tell you/us if there is a big difference, if any, between the PA3X and PA-900 keyboards, and would it be worth the change...when you are ready, of course.
Ian