Update on my Win10 experience: I've had trouble with the upgrades for my tablets, but the new 1511 ISO/release restored VLC media player to full speed and no more buggy choking on MP4 movies (just as it worked when the device was running 8.1) on my Microcenter WinBook 7.1", so hooray, it works like before... Because these 7" models are 16GB, it's impossible to upgrade with such little space so you need to wipe the drive (preferably), create a bootable USB memory stick and do a clean install.
I also ran into the reverse operation bug of the headphone jack where the internal speakers only work when a 3.5mm plug from a pair of headphones is plugged in, but I solved that by uninstalling every audio related driver in Device Manager and letting it reinstall the drivers again... This method did not work with my bigger 10.1" 32GB tablet on the older Win10 build, so I'll have to try it again after doing a clean install with the new 1511 update/release.
Conclusion: If you're already using Windows 10 and it's asking to update to with this 1511 labeled release, do it.
* A Windows 7 add-on does sound good. Am getting used to the current style, but could try that some time.