MPG tested the 2018 Mac mini 15-inch 3.2 GHz 64GB 1TB UHD630. Add 10-gigabit ethernet if it makes sense in your environment, and save money by getting 64GB OWC memory and upgrading an 8GB-memory Mac mini.
Many tests are now published on the 2018 Mac mini:
Adobe Lightroom performance
Adobe has made progress in using CPU cores over the past several years, so this test shows that the 2018 Mac mini and its six CPU cores offer a substantial advantage of the 2017 iMac 5K with its 4 CPU cores.