I agree with sticking to one brand. I have changed brands and had one tough time getting used to a new OS.
I do prefer the Yamaha OS system as it works like a computer and to me it is simple. But to each his own. I truly believe that
one brand does not totally fit the bill. I have a Tyros 5 76 note keyboard on order. May be shipped to me next week if there
are no unexpected problems. Lloyd