The stroke is longer than the PSR, and I believe the keys are weighted with small weights (my T3 is sold, so I'll have to wait till I get T4 to be certain)...they are also a little narrower than those on the Korg (which on some models, is Fatar), but the narrowness isn't enough to be an issue.

Ah, the HS-8T...I'd say the FSX is easily it's equal...the keys, if I remember, are basically alike...same width...aftertouch is consistent...again, the FSX is one of the finest actions being sold today...not just my opinion, but echoed by the many users of Tyros2/3/4 and the Motif.

Action, like sound, is subjective and personal...Korg devotees will say that the Korg has a "better" action, whilst Yamaha fans will say the FSX is superior. They both can't be wrong.

Best bet is to try them both, preferably side by side...then, add to the equation the type, quantity, and quality of orchestral voices, and then, make your decision.

Ian