If it's not too late, I can share my experience. I was there a few years ago and did the geysers/Valle de la Luna, but I didn't rent a car - went with one of the local tour outfits.

I thought the areas around San Pedro were beautiful, but I wasn't frankly all that enamored by the town - it was a bit too full of rich but unwashed Argentinean kids with dreadlocks for my taste... seemed to be where the rich kids went to slum it up and smoke lots of pot... I'm not really in that demographic

Also, I found that lodging left a lot to be desired. I stayed at two different places, one of them reasonably nice, but hot water was spotty to nonexistent. The way people talked about it, this was not at all an uncommon occurrence. I was there in the winter, so that may have had something to do with it.

Also, the prices were way higher than anywhere else I've been in Chile - including the rich parts of Santiago. That just seems to be because San Pedro is so remote, and everything needs to be sent there from down south.