Iīm a fan of using longer focal lengths (especially in the 120mm - 250mm range) for landscapes and architecture as well. However, having a 150mm, 180mm and 250mm I would not recommend getting all of them (Please donīt ask me now why then it is the case with me ;-) ) In my view it would be sensible to have either the 150mm and 250mm or only the 180mm (maybe paired with a 100mm or 120mm then). I have no use for all of these lenses and I think I might sell some of them next year...