Having recently done Sand Canyon for the 3rd or 4th time, I did want to weigh in with a new development at the top of the canyon.
When nearing the top, the canyon splits and I've always gone to the right side (which Steve Hall notes as "the very small canyon below lower dune") to attain the ridge overlooking the basin and Owl Lake. I've poked around the left side a bit but it's a boulder / rock field, and has always been way less appealing than the much easier walk over the compacted sand on the right side.
Wellllllll .... some good erosion and maybe flash flooding has happened in the last two years because the much easier right side is now all chewed up. Here's a photo of the junction start point I'm talking about, along with a vertical showing the condition of the sand bypass now. In the past when I've done this it was pretty much a leisurely cruise. Now it's choked with rocks, brush, and other random debris.
Also ... when doing the Sand Canyon hike this time I tried to keep in mind the idea of doing it with an overnight pack. It's hard to give backpacking recommendations to a stranger because I don't know your level of fitness, your physical capabilities, and what sort of gear you have (mostly concerned about weight). I'm a mindless idiot when it comes to hiking and can put down mile after mile, pretty well loaded (gear and state of mind), but I think backpacking this as a through hike might suck for a lot of people. On the day hike we did, two friends tagging along bailed out at this juncture while I shot for the Owl Lake overview ridge. My girlfriend followed like the trooper that she is, but I did resort to lying to her once or twice in the now mangled approach that "only one more ridge to go" in an effort to drag her ass all the way to the end.
YMMV.