+ Prices here in Switzerland are insane, so not sure if the scholarships are comparable Unless you'll live on the French side and drive 1h to and back every day.
I would prefer UCLA over EPFL, but mostly because I like the US style of life more than Swiss one And I believe you'll get more scientific connections in the US. It may take more time to complete your PhD there though.
But if you love skiing, definitely go for Lausanne *_*