If you leave it on a desk all day, then it doesn’t really matter, but if you’re constantly taking it on the go you’ll likely appreciate the change (even if you don’t think it’s worth the trade-off in keyboard button travel distance, elimination of some ports, opportunity missed for a larger battery, etc.).
Personally I wish they had allocated an extra millimeter of depth for the keyboard.
That really made a huge difference (the Acer used to give me backaches, as it also had a much larger power brick) but all the laptops since didn't really bother me in terms of weight.
I cycle to work every day. I found switching from a MacBook 12" (2015) to a MacBook Pro (2016) a huge downgrade in this respect (the 12" is 0.45 kg lighter).
If Apple releases a MacBook 12" with at least two USB-C ports and good 4k@60Hz support, I will probably switch back to the MacBook 12" on the next upgrade.
The weight reduction surprisingly doesn’t have a lot to do with battery capacity.
https://www.cnet.com/news/macbook-pro-october-2016-battery-l...
But it's still a reduction in capacity (from 99.5 watt-hours to 76).