For many years now I have been running Windows and slowly trying to convert over to Linux. My main way of gauging if Linux is ready for prime-time is the ability for a user with no Linux experience to switch over from Windows. Linux has made leaps and bounds in all areas, especially in games. Yet almost every time there are minor deal breakers. When I installed Ubuntu 14.04, I was left with sound not working properly when switching between USB and built in sound. It was so annoying that I went back to Windows.
My wife tried Linux Deepin, because it was so beautiful and loved it. Alas, after a month she started running into minor deal breakers and she too returned to Windows. Getting rid of all dependency on Adobe products would be a huge help. Currently Photoshop is replace by Krita. Flash is almost replaced by HTML5 video, but Adobe Reader is still a problem when it comes to secure electronic documents. Solid hardware support would be key. Finally with Wayland on the way and Vulcan we should see the ability to have a solid Linux desktop within a year or two.