Having been working in the region for a while, the life style in the alps is great. The kids are diverse and the quality of outdoor activities within 2 hours drive world class. As it is a boarding school, staff operates under the triple treat (teaching, after school and dorms)
In the past 5 years most admin have changed though and the kids stealing a car and hitting a pedestrian was definitely not in Leysin.
As to the academic level I would recommend you take a look at the college acceptance list of last year (it's posted on their website as it is for most Swiss schools). Kids at LAS seem to be happy and engaged in activities.
There are no major discipline issues there beyond the usual. Have a look at the video of a brand new sports facility online and their good professional development.
Let me know if you want to know more about this school as I work there.