as far as the switch actually activating, depending on what you compare them to you might see that there's different travel distance before switch activation. However, there's good quality mechanical switches that were made for gaming specifically and as far as I know they don't surrender anything to nonmechanical keyboards. (if you want more in-depth info on mechanical switches/keyboards and comparisson to non-mechanical I'm sure there's a myriad of info out there if you google)
but there's another factor to this, human experience in using a keyboard of certain type. If you and your son are used to using the mechanical keyboard, I don't predict that you would have any input problem over non-mechanical keyboard. If a person was to switch from non-mechanical to mechanical keyboard for some time they would have some lag input due to not being used to need to apply more pressure and slighly larger travel distance for the keys to register (but then again this would depend on what to what you're comparing to)
afaik, mechanical switches do tend to have higher pressure requirements in order to register and some have larger travel distances beyond that there's no other differences that I'm aware of.