Initially wasn't sure about this company, and was actually suspicious about all of the 5 star reviews.
However have to say that everything was as smooth as could be hoped for. Taxis from Geneva to Chamonix and back were on time. Communication from the driver was excellent and we were able to change pick up time on the way back as concerned about Geneva rush hour. Taxi still arrived in Chamonix 20 minutes early to pick us up. The price was excellent compared to other companies and despite misgivings about paying the full fare after the first trip, would thoroughly recommend using this company. Thank you and will be using you again at some stage.
I am adding this comment after the reply below.
Am totally happy to say that any concerns that I had were completely unfounded and the whole process was excellent throughout. Very grateful to Paul and his team for such a high quality service.