Not speaking for Tom...but ive got the xmax 120 and have sold and fitted many. In fact, last yeat the xmax 100 was our best selling boot.
Its all about the custom shell's plastic, it has the ability to be heated to a relatively low temp and become extremely soft. Once cooled, the plastic, unlike others, holds this new form, making for a simple fitting process and extremely comfortable boots.
You may need some extra work beyond the initial process...and of course a footbed.