If you've got good glutes, lowering the bars will close the hip angle and engage those muscles and give you more power. It's a different riding style. Going from an open hip angle where you are mostly using your quads to a closed hip angle where you are using your glutes might lower your power output until you start developing the proper muscles. On the other hand, the glutes have the potential to be far more powerful than your quads, and you'll never get there until you just bite the bullet and lower your bars.