Camelback is definitely worth doing during your stay in Phoenix/Scottsdale. Doesn't get much better than free entertainment that opens up the rest of your day to eating tacos and margaritas without guilt. You've earned it after this climb!
We have hiked Cholla trail twice now. It take about 2.5 hours round trip not counting time spent up on the summit. This route is 2.8 miles round trip. This first 2/3 of the hike is a nice hike with a fairly steady incline. For the last third, it's a steady scramble to climb the steeper incline. This was daunting to me at first but take your time and be brave. The view and sense of accomplishment is worth it. If scrambling is not for you, there is a nice overlook area before you get to that part where you can turn around or wait for your party to finish up to the summit.
From our experience, this hike is basically always crowded. The earlier you can go the better, both for the crowds and the heat. The street parking close to the trailhead fills up quickly. We added a nice 1 mile walk to and from the car just to get to the trail on Saturday morning.
Bring water! And no dogs allowed FYI.