We had an awesome time during that walk.
But the most impressive was the company, the guide and how nice there were ! The guide was really friendly and very professional as he checks for the first half hour that you have the level before going any further and top it all, they refund you the all price (minus the chairlift) if you feel you can't go any further. The guide was really honest and put safety first by letting us know the conditions of the terrain and how difficult it was going to be.
Despite the fact, we decided to go back down after half an hour walk only, I give them a 10 out of 10 for the short but really nice guided walk, the professionalism and friendliness ! Very impressed !