Welcome to cruise chat.
The platform is very small and a lot of people seemed to Bogart it on our tour last summer, even though the tour guide announced that people should give others a chance. You aren't supposed to spend the whole trip out there. I found the view quite adequate from my seat. Don't take a 20 month old out on the platform.
Heading up, the left side is where you want to sit. The right side will be against the trees and mountain sides most of the time.
It is well worth the money and an excellent train ride.