exotic case materials all have a different effect on speed.
Metals are brighter and cooler make it run faster, exotic ceramics faster still.
woods are warmer, and slow it down. Mahogany and rosewood cases look ok, but they have a speed killing effect on the unit, Dingo tone makes them marginally quicker, but then we really get into the speed case debate....

Personally i think the whole metal vs ceramic thing is hocus pocus, speed is in the eye of the game player...

Oh, and the whole red vs blue standby light thing....