I don't put a whole lot of stock in anything from Consumer Reports, but it seems like most of the high-feature infotainment systems get horrible reviews when they first come out. The ones that end up being good seem to get it the worst in the beginning. Maybe it's because they're pushing the boundaries a bit and taking chances a little.
I've played with the Cadillac CUE system in both the XTS and the ATS. Just jumping in blind the way I did with MFT when I got my Focus, CUE definitely loses points in user-friendliness. I was able to figure everything out with my MFT right away, but CUE takes a bit of fiddling with. I also don't like how Cadillac has practically done away with all the buttons. For example, the radio volume is a touch panel instead of a button. It's too easy to brush across these "buttons" and change something you didn't want to change, making it even more frustrating. This is the first release of it and I'm sure they'll continue tweaking it. There's only so much you can learn from testing something like this. You have to throw it out there in the public to really see how good (or bad) it is.
One of my issues with CUE is the fact that they put it in the XTS. The ATS buyers will generally be younger and more tech-savvy and less apt to having heart attacks from frustration while learning the CUE system. The XTS replaces the STS and DTS, so it will be picking up the core geriatric segment of Cadillac's customers. These poor people are going to need a 30-day course to learn the CUE system.