You've made good choices....Wengen has more options quality restaurant and room wise, but if you're using it as a base, it's remoteness up there translates into more travel time per day, same with Murren. But if your exploring means hiking, Wengen would be fine. Lauterbrunnen is a nice place to sit on a patio, drink bier, and watch waterfalls, but being in the canyon pales in comparison to being up above. Either of the to 'upper' towns are unworldly beautiful...you might find yourself content to just soak up the beauty...it's breathtaking up there. Grindelwald is also nice, a bit more sleepy than the others. Hotel Gletschergarten there is one of my favorite places to stay, sitting on the balcony in the morning looking at the Eiger, eating pastry from the good bakery right across the street. The cemetery across the street, towards town has many gravesites of climbers who have died in the nearby heights...it's worth the look. The train runs to Grindelwald, not so the others. You will love the area.