I tried this hike a week ago (during Santa Ana winds, not smart) and had to turn around at the backbone because the wind was too strong. I kept checking the wind forecasts and decided today was the day and it was perfect! The summit wasn't windy or cold at all, actually pretty warm. I went up the backbone trail and came down the baldy bowl/ski hut trail. I definitely felt like I was going against the current, and next time I would probably just up and back down the backbone because the baldy bowl is steep and slippery going down. I definitely felt the altitude on the hike, probably when I hit about 9000 feet. I didn't feel out of breath but I had to keep stopping to catch my breath, it was a strange sensation. But anyways, the was the hike I most wanted to complete in the challenge and I'm glad I did it!