We had quite a significant performance increase on 2017 at one job I had:
https://tracyboggiano.com/archive/2018/06/query-store-usage-and-adaptive-plan-tuning-usage/

I've already contacted Bob Ward about this and I'm currently using it on 2016 at my new job and have used to get better performance from certain queries by forcing plans.  I do recommended being on the latest CU there were some fixes in one CU for systems with lots of tempdb usage.  We were early adopters to 2016 and due to the tempdb issues we have to at one point turn Query Data Store off.