A lot of the 'private' railways in Switzerland that go to high resorts seem to carry quite a lot of goods and parcels and luggage - makes sense, especially in winter, to keep some of the vans and lorries off the road. Don't forget the BOB goes to Wengen which is traffic free.
Have you got any specific travel plans for your break this year? The ride on the BOB from Interlaken to Grindelwald and then on up to Junfraujoch is expensive and can be very busy (and is also quite a lengthy trip), but is worth it if you've not done it before. As I recall you can get 50% off with a Swiss Pass or half price card on the Junfrau Bahn and the BOB is classed as part of the national network for the rail cards iirc.
GTBE junior & family live in Switzerland and his local station is Ilanz, on the Rhatische Bahn between Chur and Dissentis. Every year we stay a few days with them then travel on by train to a Swiss city. We've done Interlaken and did the trip up the Jungfrau via Grindelwald in the sunshine (best to go early in the day for this). This year it's Bern, so travel via Dissentis, Andermatt, Brig. We usually get Swiss passes for convenience.
We fly to Zurich. Used to use Eurostar, but got fed up with unpredictable service and appalling facilities at Gare du Nord which aren't much better than Dover Western Docks used to be.
So many trips to recommend in Switzerland. Rhatische Bahn is wonderful - proper trains with locos on the front and Guard's vans, local pick up freights etc. As Chris75 says, a lot of freight is moved by rail in the high valleys. Bernina Express route is arguably more scenic that Glacier Express, but on both routes get the local trains not the named trains.
Edit for spelling of "Rhatische"
