The P-series of Yamaha's digital pianos, the P45, P125, and P515, have been around for quite some time now, and some people believe that it's time for Yamaha to roll out an upgrade. While I personally think the P125 and P515 wouldn't need to be changed very much to stay relevant for many years to come, what about Yamaha's cheapest fully weighted digital piano the P45? How does it compare to an instrument that is vastly cheaper than it? Let's find out.