Steel Guitar, Pedal Steel Guitar purchasing guide, examine action and playability. Good action, sustain, intonation, and playability should give it away.
Good action means the pedals and knee levers are quick, responsive, positive-feeling.
This is particularly important on fast leads. Playing the steel guitar is the way to check for good action. Verify that you fit under the steel guitar and that you would be comfortable playing the guitar for long hours at a time. If the steel is too tall or too short, ask your builder to modify the height. Your builder should be able to do this operation for a modest fee.