I visited for two nights to see which version of the Slab City story to believe - There are so many videos, but most of them were made by people who did not even stay overnight.

One story is the romanticized tale of free-thinking sovereign citizens and preppers working together in Utopian Fashion to survive off the grid in the deep Sonoran Desert and shun government interference in their lives.  They even have movie nights and a Saturday night open mic.  There are some folks there who deserve a kind description and they work very hard to help their neighbors when they can.  There just aren't enough of them.    

The other story is about how hundreds of conspiracy-laden, disenfranchised, meth-heads, dependent on SSI, have trashed a 600-acre parcel of public land.  This group is real too, and will solicit your sympathy and cash if they can't figure out how to siphon gas out of your tank while you're wandering Salvation Mountain.

If none of this impresses you, then by all means, visit during winter to see the clever art installations, but if you're determined to hang for longer than the day, I recommend you pay to stay at Mojo's Camp or The Ponderosa where the hosts have a care about their guests.  Do Not camp alone out in the open.  Do not accept any bliss from anyone, and do not flash your cash.   Leave the kids at home unless you want to scare them straight.