Given enough room and of course design consideration, the side lighting is meant to provide the best face light but still above the mirror is good.

So, the answer is "yes."

We chose ceiling recessed lights and above mirror because we didn't have room for sconces (which I like the look of), but I have never been unhappy with the above mirror.

I did insist on CF for the recessed, but incandescent or halogen for the face lighting.

As you state you were unhappy with above mirror- seems like a no brainer to put in the sconces! (with or without the above mirror)

How long is your vanity? You say "mirrors" so I'm assuming you will have two. You will need at least 3 lights to be effective. So you need to make sure you have enough room for the lights on the two ends of the vanity and at least one in the middle. Originally I thought I had enough room for this set up but as I considered the size of the mirrors and the proper spacing for the lights on the side I realized I would have to do over the mirror lighting.

The vanity is somewhere between 8 and 10 feet long. The discrepancy is that there is a stack of drawers at each end. If we build them high, the vanity ends at the drawer stack. Build them vanity height and the countertop will flow right over them, essentially giving us a couple of extra feet.

I've laid out a couple of elevations with some design software. The wall looks awfully busy with lights above, between and to the side. I'm considering just doing the above the mirror lights and adding a lighted makeup mirror that swings out from the side wall. Any thoughts?