One part of the Golden Pass route in Switzerland is between Zweisimmen and Montreux (super scenery), and now they have added an additional perk: on the train departing Zweis. for Montreux at 14:26 and 9:45 in the reverse direction, they are using special locomotives*, the motorman's cab is elevated, to have 8 "vip" seats up front (reservable at extra cost), which allow full frontal view of the scenery; this car is first class and has the regular panoramic viewing for the remaining seats. I just rode this train, but did not know in advance about the vip seats until aboard the train, and these were all booked up on my trip.
*the first car is both a locomotive and has passenger seating.

All railpasses valid in Switzerland are accepted (without supplement) for the entire route Luzern-Interlaken-Spiez-Zweis.-Montreux.