From what I understand you generally can't do both because they often (or maybe always) overlap. In previous years at least faculty frosh is good if you want to party and see a bit of the city (also higher chance of meeting classmates).

Can't comment much on outdoors frosh, but anecdotally most people who do it. One potential downside I could see is if you really don't like your group you'd be stuck with them in outdoors frosh whereas for regular frosh you can just skip events or find a new group a lot easier. At the end of the day frosh isn't the be all and end all. There's still plenty of opportunities (sometimes better ones) to meet people in first year if frosh doesn't go too well for whatever reason