With B&W, doesn't the "greenness" of the grass depend on filtration?
In my view, each format has its strengths and weaknesses. Which format one uses as his/her "primary" format depends (or it should, I think) on that individual's artistic objectives and personal preferences insofar as grain, detail, tonality, etc. Then, there are practical issues like size, weight, and convenience of the gear.
For me, the 120 gear is now mostly restricted to studio work. In the field, I shoot mostly 4x5 or 8x10. The 35mm rangefinder almost always tags along, however.