We just made the jump from 2013R2 to 2018 (via 2016 R2) this week with MR, Integrity Data, Greenshades and a server move/SQL upgrade. Our users haven't been complaining (too much :)) and the week hasn't been too hectic.If you have users that use Purchasing - Inquiry by Document and you maintain a good bit of history, you probably want to search for and read the GPUG forum post "AP Inquiry by Document GP2018 so slow". We currently have 13 years of history and it takes around a minute an a half to open the window. It was at nine minutes and severely impacting the system performance on Tuesday night before I upped the sever RAM from 16 GB to 20GB and changed MDOP in SQL Server to 1. The company DB that we are running this against is around 33GB. We'll probably be having a discussion in the next month about purging some history. In the meantime, we are having the window re-coded to not prepopulate.
https://support.microsoft.com/en-us/lifecycleFrom what I can see here - it follows the version of Dynamics GP you have.