I have an oldish PC, bought originally to run Vista. This I then updated to 7 and 8. This week I download the Microsoft Technical Preview, otherwise to be called Windows 10.
The installation required DVD to be burnt and then the occasion button pressing while loading.
The final loaded PC was almost exactly as I had it setup in Windows 8. All programs ran, in particular CnW Recovery. ie the upgrade could not have been more painless - although it is reported that come April, it might all stop working. It even worked as a remote desk top with no additional attention.
I cannot comment on performance as the PC is an old Core Duo but it does have 8GB RAM. I am currently using it on video file recovery testing and after a few days it has just worked.
The famous start menu is back, with a few tweaks, and a bit of the metro style start at the same time.
The only downside is that Norton 360 does not work, so the system is protected by the free Microsoft Defender.
So far, so good.