There are many different opinions on whether a student should be practicing on an acoustic or electric piano. We highly encourage the acoustic approach as there are so many benefits that outweigh the electric.
First of all, one has to understand that practicing music comes from listening to sound. It doesn't make much sense to opt out on a pure acoustic sound. Remember, that the instrument you choose will be the source of sound that you or your child will spend hours on practicing. Non-musicians may not really care about this difference, but acoustic pianos are able to produce "colours" and a wider dynamic range. The sound also becomes fuller with more depth and it alters the way you actually play.
Touch and Tone
Based on the amount of speed and WEIGHT you play the keys with, you are able to produce these variety of colours, from warm to bright, soft to loud. The electric on the other hand delivers sound based on the speed, and the pre-recorded sound (which by the way, is the only colour you get). By opting out on an acoustic piano you are missing out on all these different possibilities of sound you can create. Of course if you are a person that just plays the "notes", this won't be much of a problem.
But to our students that are always encouraged to create, listen, and make proper music, its an incredible advantage to have. When a real musician plays on a proper acoustic piano, that is when the music truly comes alive, furthering their interpretations and approach to the performed piece.
Overall Quality in Perspective
Let's put this into perspective for parents who are enrolling their children into a minor soccer league. Would you purchase your child a pair soccer shoes without cleats? Perhaps, your child may never feel the extra benefits of the cleats digging into the ground, allowing them to quickly change direction and react faster. It is the same in the sense where the musician will miss out on an integral part of their education and musical interpretation.