The Sound There can be no compromise with this. How easy the instrument speaks.
Some instruments are harder to play than others.
It does not always follow that the easiest instrument to play makes the best sound. How easy does the instrument speak. How good is the sound. This requirement needs to be up to professional standards, but lets not forget that even an intermediate player can bend a note at least a semi tone. I would rather play an instrument with character, than an instrument which allegedly plays perfectly in tune.