I have 3 laptops with Windows 10 on them: 1 works fine, 1 works ... slowly, 1 has just died.
All three are dual-boot with either Xubuntu or Lubuntu.
The 1 working laptop is a HP Compaq CQ45 with 6GB RAM and a fast Quad core Celeron chip. I use it to demo Windows 10 which I "voluntarily teach" at the City Library. Whether I boot it to Windows 10, or Lubuntu 14.04.4 LTS it works well.
The 1 that works slowly is a ASUS Ultrabook with a slow Celeron chip (1.1 or 1.2 ghz) and 2GB RAM. It's as slow as it sounds. When I boot it to Xubuntu 14.04.4 LTS however, it works much better.
The 1 that has just died on it's Windows 10 install is a ASUS Ultrabook FS502C with a Pentium Dual Core 2117U and 4GB RAM. Xubuntu 14.04.4 LTS is running fine on this one too: that's how I identified the chip, with "System Profiler and Benchmark". I have to confess the Windows 10 install is probably a hodge-podge mess, as I had used it for the preview editions, and it took booting with a Win10 1511 DVD to restore it last time it died.
As a volunteer at the City Library, I've encountered many people having problems because their laptop upgraded without them having particularly intended to.
Even experienced people have been caught out, and I've taken great delight in sharing GWX Control Panel with those who are horrified by the possibility it will happen "behind their back". I've also made careful note of the mention of Never10 in discussions here :-)
My advice to people is, if you like Windows 7 or 8.1, don't upgrade to 10. The earlier versions will be supported for what will probably by the life of the average laptop (another 4 years or so), and if they then buy a new one, they get Windows 10 by default ... hopefully a mature product by then. I have one laptop that has Windows 7 and the afore-mentioned Xubuntu 14.04.4 LTS ... and I'm guarding Windows 7 like my life depends on it. I have a desktop PC with Windows 8.1: ditto.
Microsoft might be pushing Windows 10 because it will make life easier for them, but the way they're doing it is not making life easier for customers.
I acknowledge that ongoing development and security issues change things, which is why I accept the eventual upgrading of my Linux installations from one LTS version to the next, but if I've paid good money for an operating system, I expect to keep it as long as I want to!