We love both the Lauterbrunnen Area and The Val Gardena. So much that we usually visit both each year. We do, however, spend more time in Switzerland overall because we love the transportation system and how it can take us to so many fabulous hiking opportunities.
Pros to Val Gardena: Italian food (I never get tired of eating Italian), uses the Euro, free pass for the regional buses given with lodging.
Pros to Greater Lauterbrunnen Area: incredible transportation infrastructure, snowy peaks, high mountain experiences like Jungfraujoch and Schilthorn, more day trip options beyond the valley using your pass. That is, going to Kandersteg or Brienz or Bern, cruising on a lake, joyriding through the mountains.
Yes, Italy costs less. Both have outstanding options for hiking at all levels from easy to difficult. Both have passes for lifts that are a good value (Val Gardena Pass and Berner Oberland Regional Pass).