Do you want less mirror space? Mirrors can be expensive and you all ready have full walls of mirrors. You could frame each existing mirror and replace the light fixtures. Instead of doing one large light over each vanity you could select a smaller three or four light fixture and hang two above each vanity. Framing your existing mirrors will instantly update them while adding another design element to the space.

I thought of that but I don't think I have any room for framing. There is a metal rim holder at the base that would prevent the frame from sitting flush and I also have an electric outlet only a inch from the bottom that would be covered up.

There is a company called Mirror Mates that will custom make mirror trim with cut outs in the back to accommodate your hanging hardware. You send in the dimensions indicating where the rim holder is, or small mirror clips, as well as select what ever trim style you want and they will custom make it for you. If you want to break up the space you could hang two separate mirrors over each vanity with a vanity light above each mirror. Since one is larger than the other, you might see if you can find a mirror that will allow you to do hang three on the larger side and two on the other.

Thanks for all of your suggestions. Here's my "after pictures"

I got 4" ornate mirror frames, had my cabinets refinished in a deep espresso finish, new light fixtures, added trim, changed hardware, had grout cleaned and re colored, and repainted. Looks much much better!