While I have not yet taken the free upgrade to Windows 10, I've been considering it lately. It'd be interesting to see who has upgraded.

I have not and won't. There is nothing that Windows 10 offers that I need.

I'd be interested to hear what all contributed to that decision.

Even when I had finally built my new computer, I looked into what games required DX12 and there was none. That would be my only consideration of using Windows 10 on a computer. Games. No games required it, therefore I don't require it.
 All the computers I have ever build were based on the specifications of a game. Even the hardware that is currently in my Windows 98 PC was originally spec'd for Return to Castle Wolfenstein with Windows XP.

I'm thinking I'll try it out and see how it goes. I have tried it on the laptop I have and it did run really fast. And this is an older laptop. Booted faster, everything performed faster and it was really good. My concerns were more with what all they want to monitor.

I did on my desktop, it was a pain. The update process was glitchy, I should have gone the clean install route.

Once it was finally installed, it was messed up - opening to the Start menu instead of the desktop (I hate the new Start menu, too), and no desktop shortcuts when I finally got it to display. Eventually figured out it had switched to Tablet Mode and got that corrected.

Worse problem was it broke my dual boot setup, Linux Mint wouldn't open, Couldn't even locate its files from the live disc. Win 10 had created a new recovery partition when I was already at the limit for primary partitions, so my Linux system partition was now seen as unallocated space. Nothing for it but to re-install Mint, after revising the partition setup (still have my Puppy disc with GParted on it, so the tools were at hand).

Any performance improvement is minor, and it was a big hassle - most of which could have been avoided if Microsoft had provided a warning about the partition thing.

Went ahead and upgraded Monday. I backed things up, did the upgrade, then formatting and did a clean install. So far so good. Really liking how fast it is.

By all accounts, clean installs generally go smoothly. Glad to hear yours went well.

One other thing I should mention, for anyone else who's making the move - it takes up quite a bit more space than Win 7. For my Win 7 install, I created a 50GB system partition and a large data partition, and that was fine - plenty of room. Updated to Win 10, and it filled the system partition right up - not enough space left for defragging, before there were even any updates. I expanded the partition to 75GB, and that has proved to be barely enough - I wish I'd gone a bit larger.

It's probably because if you did an upgrade the Windows 7 data is there for 30 days. I went from 10240 to 10586 on my clean install and I have a Windows.old folder that has WIndows 10240 in it. Auto deletes after 30 days though which is nice.

Both folders for me weigh in around 30GB.

No doubt that was the problem. Another reason to do a clean install, if you don't have lots of extra HD space. I just did some research and found out you can remove those recovery files with the Disk Cleanup utility, just select clean up system files. You lose the option to roll back then, of course.

You are exactly right. It's rather similar to how Windows 7 and up had options to remove old hotfixes, etc.