This is the second time we have visited Benalnatura, the other time was March 2009. (Straight married couple from the UK).
We arrived early as there isn't much usable space, even the usable sand is very stoney but it is a small price to pay for the freedom.
We've not seen the bar open yet but we've normally o ly gone for a few hours quite early and like the rest of Spain, the bars don't really open until cracking on lunchtime.
There is a path at the top that overlooks the beach where the general public can stand, so be aware of that and position yourself accordingly if it bothers you. A small compact camera with a decent zoom would capture all it needed as there is simply a sign saying no photos or videos in that direction.
There were maybe 8 others there (not including a handful fixing a wall and raking sand who were clothed), that was at about 10am, by the time we left (as it had clouded over and was blowing a cold breeze) at about 11.30am there were maybe 20 people.
In our experience it is mainly a guy nudist beach (which is fine) with a smattering of straight couples, quite a few singles and the occasional family.
Don't venture around the sharp rocks at either end of the cove if you are in any way prudish.
Great beach in a good location, easily accessible by bus - just ask for the flatotel.
We will always have a visit if in the area.