I have been running the technical release for 5 months now, it is a nice OS and will be easy to run, if you like what you have, don't upgrade, if you don't like what you have it is worth looking at. I actually like 8.1, but I have also installed a small program so I have the regular desktop with a start menu, which is what most people don't like, it was to much of a change , we were all raised with the start button and desktop. I have run the small program to make 8.1 run like 7 for a couple of years now and see very little difference between it and 7.
Windows 10, is going to be a comfortable upgrade so people can get familiar with it what we had in the past again. I don't like the fact, they will be moving more and more to having the OS running on the cloud and not on your computer.