The only thing I agree with most people here is shrooms are easier to consume.
Personally mushrooms make me feel more nauseous then San pedro ever has (just discard the core) mescaline is way more euphoric than mushrooms to me and life is just absolutely glistening, sparkling and beautiful during the day, would be amazing in yosemite.
If you plan on tripping during the day I say San pedro all the way, If you are planning an evening trip its more of a toss up but I'd probably go with the shrooms.