It's not surprising really that you'll get lots of different opinions about the pros and cons of Windows 10. Even within this thread you can see vague statements that it's a great improvement on previous versions without defining exactly how that is, or that its still a glorified beta again without defining what that means.
To a large extent it depends on just what you want to do and the only way to find out if any version is best for you is to try it. My wife just browses the internet and checks email and she could just as easily do this on XP, Vista, 7, 8 or 10 or even Linux.
On the other hand I have a large number of paid for programs that I've run on Vista, 7 8 and tried on 10 and I can't say my experience was any better using the latest OS. What really made a difference in performance was updating the hardware.
So why did I update from Vista to 8, well mostly because some of the software I was using had features added in later releases that I needed ( need not want) and would only run in Win 8.
I've run Win10 for a number of months and can't say that it improves my life or productivity. What I really don't like is the lack of control over updates and the privacy issues.... meaning unless your careful you can finish up handing over a lot of your data to MS for them to make money from. The Apps I find mostly trivial and useless and I have no ambition to have all my life controlled by MS by using their tablets and phones and I don't use the Cloud for anything
But do try it if you must but dig deeply into the settings if you can find them. Always take a backup of your data before making any changes. You have 30 day in which to roll back to your previous OS, after that you're stuck with it.
Personally I wouldn't do the update but would do a clean install.
Each to his own and good luck if you go with it