For me its much more a utility issue. Will my TPU tube have to be specific for my wheels? Can I jump from 27 1/2 to 700c? Can I go from 28mm to 34mm using the same TPU tube? Can I patch the TPU tube effectively. Of course next comes the cost. I do like the small foot print the TPU tube has. I do like its weight but for me as a clyde ridding a steel bike it is not a real important issue.

As the quality of Butyl tubes and the cost of TPU tubes decline I am soon to make TPU tube purchases...