Ray, my notes for you:

1) Trail 44 (South Coyote Trail) has a nice large (huge) almost empty primitive campground after the rocky climb, in the Sheep Canyon. It is well suited for large gatherings and wild parties. Once I saw the whole club of Hummers camping there, may be 50 or so of them. You may have a good night there, if it fits your plans. And again, I like that trail the most among others.

At one point, the road finding may be confusing along the trail 44. At that point, by the river, you are arriving to a seemingly "dead-end" and it seems that there is no where to go. The park signs do not help, they create impression that the area is closed. The trick is that you have to drive directly in the river, and drive about 100 feet between the trees in the water along the river, and then you will see the opening to the left and you can exit the river.

2) Trail 45 (Calcite Mine) is very nice. It is not about the driving only - it provides great exploration area in the end, where they mined calcites for optical devices in WWII. And it is very scenic. But the trail has two issues: first, it is relatively easy - I do not understand why they marked it "difficult", it is "moderate", at best. The second issue is that it is very difficult to find. May be, they meant exactly that - "difficult to find". I had all GPS coordinates but I drove 5 or so times back and force on the road while I was able to find it. But it is there.

3) The area around trail 48 (The Slot) is great. But the drop-off is very soft and very steep and long. My vehicle was sliding semi-uncontrollable downhill. That drop-off is MUCH more difficult than the Diablo drop-off. I made it south-to-north, then I proceeded to S22 road in north-west direction.

4) The Fish Canyon in the trail 57 may be the most scenic place in Anza Borrego, in the right light - so bring a good camera. Diablo drop-off is not difficult in both directions. I used my front locker but I'd make it open. The little short climb just before the Diablo drop-off (in north-to-south direction) is more difficult and requires some kind of traction device or a very long-base vehicle.

I believe you guys will have great time there. May be I'll be able to come to Anza next winter. My kid may be ready for some exploration by then.