Well it has been over a month since I started using Apple computers again and I have to say that while there is a bit of a learning curve related to the file system, I am enjoying my 20 second boot ups and fast response in Photoshop and Lightroom. The Apple SSD is very fast. The 5K monitor is fantastic and my G-Tech Studio 6TB Thunderbolt drive is fast. I also purchased the Apple Trackpad 2 and use it along with the Mouse.
Just from observations I would say that the iMac software makes better use of the installed memory (24gig). I am sure there are some specific applications that use memory better than others, but I seldom saw my Windows 10 machine use more than 12 of the 32 gig available. I see the iMac using 16 and 17 quite frequently while using Lightroom and Photoshop (the same apps I used on Windows). The 5K screen really helps deliver accurate colors and reading text is very easy on the eyes.
I also purchased an iPad Pro for my wife's birthday. She has been using it to create greeting cards and wireless printing of pictures to her Canon Printer. The iPad Pro is a much better experience than the iPad Air based on it's real estate alone, and for Valentines Day I bought her the Apple Pencil which she likes as well.
Here is a picture of a custom 1937 Chevy Pickup truck I took in August 2007 using a Sony DSC-H5 digital camera. I used Lightroom to bring out the color of the truck and emphasize it through a vignette. When doing "extra" more heavy duty editing on a picture I do hear the fan speedup from time to time, but normally the iMac is very quiet on everyday tasks like surfing the web and reading emails.