I like the use of telephoto lenses in landscape work. Of course as already mentioned it depends upon the compositional needs or isolation of the subject outcome you are looking for. I not too long ago bought a 180 for my Mamiya 6x7 and found it has worked well for several recent landscape shots. It would be hard for me to know if a 250 at this point is necessary for future comps, but that is what makes things interesting out in the field. I would also add that my jump was from a 127 up to a 180 and not say a 150 to 180. So, the difference for me was noticeable and fits my needs to date.