I have 3 bikes that I ride regularly and have Thomson's on all of them. I have had Specialized and American Classic posts fail on me. No issues with the Thomson's.
They are lighter and stronger and more adjustable than pretty much any other post on the market. Looks is subjective, but the anodizing on the Thomsons must be superior to some other posts since the seat bag on other bikes have worn through the finish on some cheaper posts as well as some nicer ones and the Thomson posts are still PERFECT.
Just because the incremental gains in performance are drastically reduced from say, a steel 2-piece post vs a cheap Kalloy Aluminum post, does not necessarily mean that a nice post is not "worth it".
A Corvette Z06 can arguably do 95% of what a Lamborghini Murcealago can do, but I doubt that the Lambo owner cares nor thinks about how much money he/she could have saved on a Vette.