Windows 10 is a solid operating system. I like it and I use it on all my machines and there are no drawbacks compared to Windows 7 or 8. The backup is better than Windows 7 (simpler and more reliable) and the speed is good. The Start menu is almost the same as older versions of Windows. You don’t need to touch the tiles, though the Weather app is nice. Microsoft is pouring all their resources into making sure Windows 10 is a success. Don’t be afraid of it! If you hate Windows 10, it may be time to switch to Mac.
One possible pitfall for Microsoft is the forced updating in Windows 10. Microsoft has very poor quality control and testing for their updates, so they break things once in a while, and Windows 10 forces those updates out. They must improve this aspect of their system or people will defect to Macs, which have less problems. Macs aren’t perfect and they are more expensive than PCs, but they are less trouble.