There are a couple of things I don't like. But there are always a couple of things I don't like about new OSs.
One thing is how incredibly talky it is. Some actions that used to just take off now require you to confirm that you really really mean it 2 or 3 times. I guess there are probably settings that could turn off some of the redundant querying, but they have me scared that it might compromise my security.
There seem to be an aweful lot of firewalls in effect and I don't know how to get to them all.
It has a tizzy about "fullscreen" DOS applications. This makes it impossible to install many old and wonderful games (these games are a hobby of mine). The games need not be DOS themselves, but many of their installation processes require both "fullscreen" DOS and Windows support. You can't have the DOS support for that in a run window now, and you can't get any windows support nor launch a Windows process in any of the DOS emulators (like DOSBOX). So you are pretty much screwed.
There's a rumor that you can screw around with your video card to get the kind of "fullscreen" support you need. I am not yet so desperate as to try that.