I have a 2-speed which runs 8 hours during the night (a 45% rate reduction in my area) on low. I use the high setting only to backwash/rinse and when I vacuum.

I installed a PoolSkim which does an excellent job of collecting the big stuff: leaves, bugs, pollen, dog hair. I put a skimmer sock in the skimmer basket to catch the fine debris. With this method I vacuum at most once a month.

We've not noticed an appreciable increase on our power bill since we got the pool.