We are flying into Zurich with plans to go to Lauterbrunnen for a few days. Would you recommend taking the train via the Bern route or the Lucerne route? The Lucerne route looks to be more picturesque while the Bern route seems to be quicker.
Absolutely take the Luzern route to Lauterbrunnen believe me
Agree with Jazz + Travels
Another vote for the Luzern route. The good bit is between Luzern and Interlaken. Past lakes and over the Brünig pass. It is actually shorter than the Bern route, but slower as it winds through mountains instead of going round the Alps.
Your initial assessment is correct. The Luzern - Brunig route is considerably more beautiful, with mountain passes and lakes and mountain towns, and a ride along the Brienzersee, all on a narrow gauge cogwheel train from Luzern to Interlakon Ost. The route via Bern is faster, and still fairly nice from Thun to Interlaken Ost.
you could if you wish take the boat from Brienz to Interlaken Ost and join the train to Lauterbrunnen there. The trains connect with the boats but check the boat timetable before you do this.
Added bonus---the Luzern route is a little less expensive.