The only thing you can find online is usually catering to rich western tourists or "expats" and usually boils down to "Which place is the most western/ High GDP and McDonalds!" so I'd rather get an opinion from someone that's been there that isn't a business tourist.
All the cities seem great to me. Guizhou, Chongqing and Kunming stand out, but I've got lots more to see.
If I had to pick now I'd probably choose Chongqing just because it's bloody massive and has everything
Same, I dream of going to Chongqing