I've also been trying out the demo for the last couple of days. So far I'm really unimpressed with the UI. It's like a program written in the 90's.
I'll give it a shot though, but since I'm not unhappy with the results I'm getting from LR, including NR I doubt I'll be switching. It's not terribly expensive though, so who knows.
I'm coming to a similar conclusion and even realization.
Looking closer at C1 in other places, most arguments come from an ability with C1 to get a better result than LR WITHOUT plugins. The thing is that with plugins, I get a what I want out of LR, and I honestly don't mind the plugins.
The interface on C1 is a bit difficult for me to use. I suspect it will be better if I can learn it, but I do think it is pricey enough that I'm not willing to take money that could otherwise be put towards a new lens or other item.

