Guys, I'm looking at BL-MT201/BR-MT200 F/R sets vs BL-MT401/BR-MT410. The first thing I took note of was that both used the same Shimano B-type pads. But what are the actual differences - if any - in design and build quality? And do they matter in the real world (by "Real world" I mean a 20-inch folding bike ridden for errands and fun on mostly flat ground, rather than an all-out canyon-shredding MTB.)