That's a good summation of the Palm Canyon area. I would definitely emphasize the 4x4 Queen Canyon side trip... it's gorgeous, with impressive canyon walls and mountains. The old Kofa Queen Mine is also tucked back in there.
There are plenty of other trails that cut through Kofa north-south and east-west that are also worth exploring (in the cooler months). I came across old cabins, natural springs, monuments and markers, mines, and very interesting backcountry views.