The Touch Bar is gimmicky, for sure. The only useful feature (in my opinion) is Touch ID. Otherwise it's an unnecessary battery drain.
Why did I switch? It boils down to this: after 13 years of being a hard core Mac user, it feels like Apple doesn't care about the Mac any more. It feels like all they care about is the iPhone.
This Dell? It's a better "MacBook" than Apple's MacBook Pro. Beefier CPU. Beefier GPU. Twice the RAM (32GB).
I want raw power, to do my work with. Apple cares more about thin and light, at the cost of everything else.