My wife doesn't look out the window much but strongly prefers facing forward. Even on short trolley rides, if we have to face backwards, she wants to change seats as soon as a forward-facing seat opens up. I prefer facing forward. When I commuted on VRE, however, I liked facing backwards because the seats are not fabric covered, and while the trains never accelerated fast enough to make me slide off, the deceleration could make me slide on the seat if I was asleep.