Both have their advantages.

With a small camp, you're much less likely to have late-week drama over spilled milk. You're also much less likely to have the numbers/money required to build comfortable infrastructure, like shade or a functioning kitchen. There's more accountability, which is great if you are camped with people who can handle themselves, but on the flipside, people who need a ton of support to survive will drag everything down. This also goes both ways, though - if you have a small camp of rockstars, you're going to be doing something awesome.

With a large camp, you're more prone to drama. There's less accountability per individual, which is both good and bad. One bad apple won't bring things down, but you also probably will have a tough time figuring out who exactly left the piss jug for strike to pick up. There's more hands-on-deck, so it's easier to build and bring big stuff. There's more money for the camp as well, most likely.

I personally like a smaller camp better. A larger camp will probably be more comfortable, but a smaller camp, in my experience, has less drama.

I was in a big camp on A street one year, and it was my least favorite year. The entire camp was very active, so there was no real room to escape from the madness; This was also partially a failure of the organization of the camp, as we built no private space. The camp was large enough to where I couldn't remember everyone's names, but small enough to where I could remember who it was that had the great-fucking-idea of playing with fucking glitter. I also brought my parents this year, and the entirety of the camp, beyond the organizers and myself, treated them like they were aliens. It was a very shitty experience to bring my parents to this great place that I had loved and to have them ostracized from camp for being older, and it's caused them to not come back to the playa since. It was nice to have a porto-potty, a kitchen, big shade for my tent, and food always laying around, but everything else was shitty.

Every other year I've always just showed up and created a camp on the spot. I don't really try to plan with friends. Last year, I tried that, and it all fell apart twice. Once in the middle of summer, when I realized that there were a select few virgins who were depending on me to do everything for them, and once when we got there, and people who claimed to be heavy-hitters ended up being drains on the camp. One guy forgot to bring the entire bar that we had spent a ton of money/time building and decorating... another gent didn't realize that we had no community trash or kitchen in camp, and he didn't understand that dirty dishes are kind of like cancer when left overnight in a nasty mixture of water+soap. Every other year, I've just gone and shown up and had a 2000% better time. That's the plan this year.