My son and I really enjoyed this workout hike. The 40th Street Parking lot had been full, as evidenced by the cars parked along the street, but there were several spaces available when we got there at 0900 hours.
There were only about 20 other hikers on the portion South of of Phx Mountain Preserves trail 100.
The views of Camelback and Piestewa are great (see photos). The trail is quite rocky in places, but I felt it was more enjoyable than the other popular hikes.