I used to get my microderm at a dermatologist office. She would make several passes and my skin would be more raw/red when I left. I switched to a day spa (because I moved) and the new lady now makes one pass. My skin is less raw and red when I leave. She says it's because she's using a newer tool, that has a more high-powered vacuum and crystal thing. Is that legit? Should I switch back to a derm office and several passes, or do more passes not matter? I would love your advice. Thanks!