I've found that a slightly longer (~100 lines) webpack config allows me to use all the caching and fancy tricks I want and is still just as debuggable. I think the main thing is setting it up yourself so you know what all the plugins/settings do.
Caching was a major dissapointment for me. DllPlugin is a nightmare to setup and other caching plugins I tried don't really speed things up. What eventually worked for me is HardSourceWebpackPlugin [1] - two lines added and went from 2min to 15s (with a tradeoff of a slightly longer initial build).
I got the same message. Still, having faster builds with one additional plugin without configuration needs on projects locked on 4 or waiting out the transition is a plus in my book :).