Things aren't always as clear cut as they seem. If the wind is calm, then you will may have a more relaxing trip by flying high above the peaks (and I would recommend 3500ft above the peaks, as this guarantees you the 1000m clearance that you need if you want to fly over a national park (in France.... not sure of the regulations in Switzerland)). However, if there is wind, which there usually is, the situation can be very different. The turbulence at altitude can often be severe (by light aircraft standards), and paradoxically it can be calmer to fly well below the peaks and clear passes at the lowest possible altitude. That does require you to know precisely where you are at all times, and to understand the rudiments of mountain flying, so it's probably better to wait until the wind is calm.
You should be careful of the forecast winds aloft. In the mountains they can often be different to what the forecast indicates.