I've had a 2016 15" as my primary machine since launch and the keyboard has been fine for me. I pretty much always use it on my lap without a keyboard cover or anything so it definitely sees it's share of debris but the temp probably doesn't get too hot because it's not usually pushing a monitor in clamshell mode (I have a desktop for heavy work). Not sure maybe I've been lucky but I definitely haven't babied the computer or anything and it's been fine.
I guess overall the 2016 has been the best laptop I've ever owned the power for the size is really amazing, I still love the screen on it, love the audio, I actually really like the butterfly keyboard on these because the keystrokes are large and accurate and the keys have very little wobble, the trackpad is actually really great, donglelife is really nothing for me I put one adapter in my bag that has every port I'd need (replaced all my usb A cables with usb c cables for a few $ a piece on monoprice) and I actually really like being able to charge on either side. Overall it's been a great machine and I think the proof is in the fact that I'm not all that interested in replacing it.