I have heard unverified speculation that the oven heats slower with a hidden bake element. The benefit is cleaning I think. I heated my old coil oven to 400 degrees in under 7 minutes, and folks with a hidden bake element take 12 or so (some take much longer - like 30 minutes)

I think the hidden is for self-cleaning, so that the works don't have to be burning off gunk, and to have a smooth surface for creating the ash.

Some hidden element ovens heat up very fast, or have an optional fast preheat. I can't give you a list of which ones though.

Another notion: My mother's old Chambers oven used the broiler as well as the bake element to preheat. In an oven that lets you control which element you're using you could do that as well to bring the cavity up to heat faster and change to bake only before you put your cake in. But then, maybe those are the ovens that already have a fast preheat.

I have the opposite problem. I make some traditional things that require starting in a cold oven and coming to heat gently. A fast pre-heat will kill them.

The hidden element got put in to give you an extra rack space (2") as well as a smooth bottom for cleaning.

As to heating slower, certianly it does heat slower. I would much rather have one without than with. Whirlpool used to make a model with a 'recessed' coil. It gave you the extra room without the heating issues.