To get the comparison out of the way: No, I wouldn’t take this over the shooters on the Pixel (my personal favorite), Galaxy S7, or, to a lesser extent, iPhone 7 Plus. Compared to those, it requires more fine-tuning to get the most out of it, its colors aren’t as vivid, and its HDR mode is just about useless. The optical image stabilization isn’t the strongest, either, so you have to make sure you have a steady hand. Plus, there’s more of a learning curve to the app.
Some of that comes down to personal preference, though. On a technical level, the Mate 9 captures tons of detail, produces very little noise, and is consistently great at getting the right amount of light into a shot. It doesn’t go haywire in darker settings, either.
It’s all good, and I can’t see anyone complaining about it — I just can’t see anyone going out of their way for it, either.