When-ever the weather is not really perfect to take the train to Jungfraujoch, to take the train to Kl.Scheidegg makes sense anyway, and mostly this part of the journey is included in train-passes anyway, while the last bit of the journey has to be payed seperate in most of the cases !
In Kl.Scheidegg you have to change the train anyway, or go back bythe same train. Trains never run Lauterbrunnen - Kl.Scheidegg - Grindelwald. They even have different colors and different inscriptions, so you wont confuse them.
While I was there, I saw the IMAX-filmteam there waiting fro their helicopter...

