Minor correction there, Willy Dog. The toilets at Shasta Horse Camp are nice composting toilets, not pit toilets. They're typically very clean and function really well without the smell of a pit toilet - better than your average Forest Service campground vault toilet. The spring water there is also amazing.
So Horse Camp is a great first night for those who have time to acclimate and enjoy the accommodations before having to poop in a wag bag and melt snow, especially for a weekend warrior from sea level. If you really want to maximize your odds and enjoy your hike, spend one relaxing night at Horse Camp, then pack up to Helen Lake and practice your self-arrest skills on the surrounding slopes - perfect place for that. Get an alpine start the next morning and join the pre-dawn parade up avy gulch.
The sun rises on the other side of Shasta, which produces a really cool shadow looking east when you turn around and enjoy it. Makes me forget the pain and want to go again.
