2015 MBP Broadwell Core i5 with 8 GBs of RAM. I have two Windows VMs with Windows 10 and 7. It depends on what you are doing and I don't always run both. I use both for documentation and support. To be honest, for what I do which is live in a web browser, iTunes, managing my modest photo library, occasional dive in Photoshop CS6, 8 GBs is more than enough. I have been using an HP Z210 Workstation with 8 GBs of RAM for years and it never slowed me down. If you plan on working 4k Video, process large data sets, maybe like run a Docker container with SQL Server Linux, have Photoshop and a couple Windows VMs running simultaneously, then the 16 GB of RAM will be handy. As a form of future proofing, you can never have enough RAM.