Previously I have used Win 7 & 8 and after its launch I have upgraded to Window 10.
As per my experience Windows 10 got many add-on advantages which is as follows: -
User interface: It got the batter user interface as compare to previous versions. You feel to work automatically.
Performance: Working speed of Windows is faster than before.
Boot time: It takes very less amount of boot time as compared to Win 7.
Best feature: The feature Most liked by me is Microsoft Cortana. I love to ask questions and got the almost correct answers.