I don't really buy the "aren't they thin enough already" argument. I would've said my 15" MBP 2013 is small and light enough, but the 2016 model is notably more livable. The reduction in footprint (which also affects space for a battery) makes it a lot more manageable to spring for the 15". It's a pound lighter than the 13.3" polycarbonate MacBook I had a decade ago!