For 35mm systems, my favorite focal length is 40mm. So for an X2D, I have often used (and appreciated) the 45P, since it equates to a 35mm lens and the next closest was 65mm, which equates to 51mm. The 30mm was not close enough to consider (being like a 24mm). With the V lenses, I'm not as clear, because the 55V equates to a 43mm. I appreciate the quiet shutter of the 45P and the small size, but the 55V is also very quiet (even quieter, perhaps), is not much larger, and has more functionality. So I'm now a bit torn on those 2.
But you did mention landscape, so it really comes down to whether your dominant preference is expansive landscapes (which would favor the 38V), or perhaps more isolation (or more distant vistas), which might favor the 45P. Personally, I would probably opt for the 38V as a dedicated landscape lens, since there is the potential to crop into some of those 100 megapixels.
Steve Hendrix/CI