I got so much useful information from this forum I wanted to add my recent trip to contribute what I can.
Me(30) and my brother(38) summited whitney on 9/2/2018, it was an over-night trip we started on 9/1/2018. Camping like this was a first for both of us. Some out of order sporadic notes:
-Weather was GREAT! No issues there.
-We camped at consultation lake. We did not find an "Easy" path down to the lake, and were surprised by that. It's a little extra trek down, and back up for the summit, and then another up-hill to get back out once you are leaving the area. We were exhausted at this point and the thought of having to climb an extra bit just to even get to trail camp the next day was de-moralizing for me, but we pushed through. However the benefit was a nice view, hardly any wind, and quiet area.
-I live in Ohio and used stairs, treadmill, etc, to train for this, while wearing my full weight backpack.
-This hike kicked my ass, I was not ready for the elevation. We drove from sea level to whitney portal and did about an hour of pre-hike, stayed in the lone pine hostel, then started the hike at around 11:30 the next day. I was dying after reaching camp, and was afraid I would never catch my breath or be able to complete it. Staying the night at elevation however did AMAZING for acclimating. My muscles were never sore, I just couldn't catch my breath and was exhausted. Altitude definitely affected me.
-It was a lot more beautiful going up than I thought it would be. Lakes, meadows, streams, etc.
-Our second day we left camp at about 6:30am, summit around 11:00, stayed for almost an hour, and made it back to the parking lot around 5:30 after packing up.
I'd be happy to answer any questions!