I am writing to express our grateful thanks for the installation you carried out earlier this week. We are both thoroughly delighted with both the very slick quality installation you completed and as for the effect, (already) well, I am amazed at the difference.
It sounds an old cliché, but the difference really is like changing. I had no idea the real obvious difference the installation would make, operation is quiet too, quite unobtrusive. Even shaving with an electric shaver, which I still do, is a totally different experience, faster and smoother, after washing first.
Thank you for a first class service, highly recommended.