You have the last good one. My 2015 died and my employer gave me a 2017 that promptly died 3 months later. Apple Care and the genius bar were a pretty shitty customer service experience but I eventually got it back. The keyboard is worse than the rubber domes on the $200 Walmart Black friday special I got several years ago. That's not a joke. For the 2017 model Ram maxed out at 16gb which made it a laughing stock for that era. The touchpad is bigger and still good, but feels substantially worse than the 2015. After a year the battery life was a joke @ <50% brightness. It doesn't feel noticably faster than the 2015 either.
My 2015 was the best laptop I've ever used by a longshot. Thinkpads of the same era match it in build quality and have slightly better keyboards but the touchpad and the Mac workflow are something I grew to love.
The keyboard on the 2017 was so bad when a coworker with an old model was showing me how to do something on my laptop he genuinely thought it was broken.