I have a variable speed setup. It was worth the extra money to me not to get woke up when the fan kicks on. Both the air handler fan and the compressor fan smoothly ramp up to speed quietly. Whereas the old setup the fan would kick on, the compressor was really loud, sounded like someone kicked it to life.

My HVAC is in what amounts to a closet in the middle of the house and shares a wall with the master bedroom.