Tips to choose a good piano

Since I played a real piano, I do remember the hardest thing is to play quietly, so if the touch feels light that's probably on the more accurate side. You will need to play the pianos and determine if you even like the sounds of their strings. Coming from an electronic keyboard background, it might seem like kind of a shock to play a real piano. Good pianos are able to adjust to how hard you play the keys. In my opinion, real pianos do this much better than any electronic keyboard I have played.

Feel is subjective, so you should go to a piano reseller and walk around their showroom playing a whole bunch of grand pianos to set your expectation for how the best pianos feel. You're not going to find anything but a grand that feels just like a grand, so you'll have to decide for yourself which areas you are most willing to compromise. A good piano keyboard should have an even touch so that when you play a scale with equal force each note comes out the same volume. There shouldn't be too much loose movement and clatter, though some is normal. This can be regulated to a degree by a technician - but why HASN'T it been? Buying an unloved piano is risky.

A lot of the uprights and digital keyboards I've tried have a sort of light touch and is really easy to produce loud notes. Sometimes, they feel like the weighting is a bit too light as my fingers sink into the keys really easily.

Regardless of brand new or used pianos, check the piano Dynamic range, Inharmonicity, Overall tone-color, Non-harmonic tones, Effectiveness of the dampers, and of releasing the sustain (right) pedal.

As the piano string is first struck it vibrates in a vertical plane, transmitting maximum energy to the bridge. With time (typically from 0.5 to 3 seconds), small geometric inaccuracy results in the plane of vibration of the piano string beginning to rotate significantly, so that some or all piano strings may vibrate out of phase and in a plane that transmits less energy to the bridge. The piano strings of a piano are the engine of sound generation. The more piano strings, the more uniform the after sound because the more the rate of energy transmission is statistically smoothed. To produce a pure sound a piano string must be of uniform density and cross-section or it will emit a warble or range of frequencies known as a false note. If the bridge pin is not firmly encastered in the material of the bridge then it also may flex and sound purity is lost. The ingenious Stuart bridge agraffe has eliminated the requirement for bridge carving and provides a uniquely definitive termination to the piano string length. In consequence the Stuart piano is virtually free of false notes.
Each note on a piano may have between one and four piano strings. Historically, multiple piano strings in the upper registers were employed in a belief that they increased the sound level; however, they have other effects. In this mode the quieter singing ‘after tone’ is generated. False notes also arise if the length of the piano string is even slightly indeterminate. Bridge carving so that the piano string length is determined precisely by the bridge pin is a highly skilled job, and vital to the purity of acoustic energy from the piano string.