So I'm a relatively recent transfer to the SF area who only recently returned to playing alliance after having been playing other larps in the northeast for years, so I might have some perspective you'll find relevant. My partner and I brought our old characters in to Enerret -- and it definitely seemed like we were well below the average level. We also started new starting level characters for Maelstrom at the most recent event.
I highly recommend the new character experience at Maelstrom. They give you a lot of lore that most of the PCs don't have (since most are from other places, which makes sense since the campaign is just barely after the apocalypse). It feels tough and crazy and exciting and was a real blast.
Game sizes seem to be smaller out here - think 20-30 people. Probably 2/3 of the characters are played in both campaigns. If you are used to the heavy team based campaign style, teams are much less central out here -- its much more of the town all working together to survive. Folks seem to be super welcoming of new community members. There are a bunch of fighters who swing 25, a bunch of folks who seem to have full columns of 9th list spells and lots of formal levels, and it seems like things not specifically targeted at low level folk default to swinging around 10 damage with big things swinging more. Mods seem to be generally scaled to the weekend APL and only when specifically hooked for low level, scaled for the group going. With that said, at the most recent Maelstrom event I grabbed all the low level characters and did an APL 4 mod that was a blast, as well as a "river boat" mod that was half low level folk that was very appropriately scaled, brilliantly written, skillfully staffed, and amazingly fun.
One of the things that may not be obvious from the published schedule is that there were multiple 1-day Enerret events that were scheduled opportunistically 2-4 weeks before the event. I think I've attended 4 which are not be showing up on the website schedule so far this year, and there is 1 more coming up. The Enerret one-day events tend to be a lot of fun and super easy to attend - just show up with your character, costume, and a lunch. So if you are at all on the fence, the one-day events are an easy way to try things out. We've brought a brand new larper as well as a person new to alliance to them, they both had a blast.