I've attempted to respond to your question several of times, and each time I've deleted my response.
I have not seen any comparisons on the two operating systems, but have ready many posts in favor and disfavor of both. My personal conclusion is that many people have a fear factor of moving to a new operating system until they see a lot of positive reviews.
Saying that, I can only draw from personal experience. Although not an IT person, I was responsible for many computer issues in our office prior to my retirement and worked with Win NT4 and the migration to Win 7 Professional. At home my wife runs Win 7 Home Edition on her laptop, and my current computer has Win 8.1 - updated from Win 8.0.
I am very pleased with Win 8.1 and found it little different from Win 7.0 Professional except for some added features and new front end (Start Menu). It appears to be more stable than its predecessors and has the usual issues with any new operating system.
Saying that, I have had my ups and downs. There were several applications and older hardware that I could not get to function with Win 8.0, primarily because they were not designed for the 64 bit system despite claims of backward compatibility. The biggest issue I encountered were the video drivers - when I migrated from 8.0 to 8.1, I had inadvertently installed older drivers that gave me a BSOD on occasion. That has since been fixed.
Don't know if that helps, but that's my perspective.