Can't really camp at Trail Crest -- it is a small area at 13,600' where you top out after climbing the 97 switchbacks. The views are tremendous but not really a place to camp.
The usual camping areas are (1) Trail Camp, at about 12K, and (2) Outpost Camp at about 10K. There are other places, like Lone Pine Lake, Consultation Lake, and above Mirror Lake but below Trailside Meadow, that are used less frequently. Not sure which you have in mind from your post.
I'm pretty sure Bob means Trail Camp.
Splitting hairs for fun: Actually there
are some camping spots near Trail Crest on the west side -- built by the trail crew who originally built the trail. I saw JMT hikers using them last year. And you left out one more in the list of "other places": the summit.
(these sites are usually used by longer-distance hikers who come up from the other side, and requires starting up with about 4 liters of water)
