I use IE 11 on all of my machines. With zero problems. None. Zilch. Nada.
I actually have 11 machines in this house. Two have Windows 7, nine have Windows 8.1 (one of which is a Windows 8.1 tablet) and one of those is dual booted with Windows 10 Preview.
I do run Windows 7, Vista, XP, 10 Tech Preview, Ubuntu, and Zorin 9 in virtual machines.
I know you'll call me crazy, but so far, only a few of those rigs run Stardock products. I use at least 5 of my Windows 8 rigs as Microsoft made them.
I have a few touchscreen machines and have gotten quite used to the new UI.