Buggers, but Beautiful
Steer Gulch...the last camp on the river.
I have always been of the school of thought that even the worst camp on the San Juan is better than most other places. That being said, there could be better places, but it could be a lot worse.
I beleive you are referencing the mosquitoes when you say "mozzies" and this is correct. I would bring my bug juice, extra bug juice and if the water was high enough for more cargo, a screen-tent for sitting would be awesome as well.
I have only camped here once myself, but floated past and looked carefully a number of times. The standard area for the camp is nice, on the smaller side, but adequate for most groups. Take in consideration that the tent pads and obvious kitchen area are right under a major pour-over and if the side canyons are rocking, or there is rain, or there is rain on the mesa, or any number of factors...the canyon could flash and wipe out your whole camp. I would scout the area well and consider the weather and other factors before setting up.
Also, for entertainment, the canyon itself goes back a ways...I have never taken too close a gander myself, but I would imagine you could scramble for an hour or so back into the drainage before getting cliffed out. That being said, the last time I went down past there, with my fiancee' in March...we thought we spied a neat little surface site up in the second level on the down-river side of the canyon...about 30 yards in and up on the left if you are looking at it from the water. I tried with my mind to locate a route up there, and I bet it would be doable if you had the time, patience and possibly more guts or experience than I do.
Last night on the river either way. Enjoy. The paddle-out the last morning still sucks even though it is only 3-4 miles...stay in the channel.