I was in site #122 in the Cenizo Loop ($16). The $10 water-only tent sites weren't reservable and I needed the assurance of a site with a later arrival planned.  I arrived at 5:02p and the office had closed but my name and site were posted on the board and the person who was there said I just needed to return in the morning by 9 to check-in.

This loop was~80% occupied. I appeared to be the only tent camper, the others were RVs, vans or trailers. The sites are close together and sounds from more than one neighbor were regular, but not too annoying (save for one younger parent riding through with a boom box playing). My particular site didn't seemed cramped because the back side was brush, but the cleared space for a tent was limited and required  shortening the guy wires. 

Restroom w/showers was just one site away and didn't cause any noise issues. The facilities were marginal but functional, didn't use the shower.

Overall I'd say this would be average expectations. Definitely recommend studying the maps to choose a site carefully depending on your own priorities.