Great touch, but could sound more convincing. I mainly use the P-45B as a MIDI-controller for soft synths and piano plugins. It's pretty great for that, the weight of the keys is pretty realistic, compared to an actual piano.
The onboard piano sounds seem okay at first, but they become a bit unrealistic when using a sustain pedal. Then, it becomes pretty obvious that you're dealing with something digital.
One other thing I kind of disliked is the weight, it's still relatively heavy for a stage piano.
If you are looking for a decent entry level piano to study or to play low key gigs, this Yamaha will do. But if you are looking for something that has both a realistic feel and sound, you should definitely go for brands like Nord.