Almost every "competition" amp I have seen has had components upgraded (higher voltage rating, etc) in order to be able to run the amp at 16-20 volts. This is not "snake oil",it is only setting the amp up to be driven to the absolute limits and beyond of the output transistors ratings to where when it breaks...and it will, to save the low dollar parts they can't make big money off of. The money is in transistor replacement and the less that has to be done to get the amp back up and running is better for them. Many of those bigger amps don't last over one shootout without having to be rebuilt. But the money they chance to win will most of the time well pay for the repair.
A stock run of the mill amp can't take the abuse that the competition amps do.
BC