Thanks very much for the welcome and answer. I really fancy the PX5S actually but it's good to know the cheaper alternative of controlling my existing module and/or VSTs with the PX-150 will give me just as good keys.
Is it true that the PX-150 and PX5s have the same keys? If they were both connected to an external sound source via MIDI with the onboard sounds disabled, would they feel the same?