Interesting comments, thanks for sharing.
Rather than springing for a new iMac, I'm considering sticking with my minimally workable early 2009 iMac but ditching the Wacom tablet and replacing it with an iPad Pro+ Pencil both as a stand-alone tablet with the Adobe Mobile apps and as the input device for the iMac.
However it means a workflow sea-change and that's always tough.
Currently I shoot RAW and use a RAW>ACR>Photoshop workflow. Bringing the iPad Pro+Pencil into the mix would change that to be a JPEG-based workflow: I'd shoot RAW+JPEG but process the JPEG as much on the iPad as the iMac, and essentially archive the RAW for occasional high resolution editing.
Using the iPad that way should make web-based sharing and posting much easier. Feedback welcome...