I'm not a piano player so I love the Light FAST key action on Yamaha arrangers. It took a while but the S950 after 50 gigs is really starting to come to the front of the pack and impress me every time I play it. There is something Sonically different in a very "good way" vs all the other PSR/S arrangers Ive owned including my old Tyros also thru the years....can't put my finger on it yet but all I can say I'm enjoying performing with it so far.