I've had my Cameo for just about a year now. I haven't used it to it's full potential - but I'm working on it!
From a group on FB I've learned SO MUCH - enough that I'm cutting vinyl in the most intricate cuts especially for Christmas. In fact, my first vinyl project was a glass Santa block that still blows me away. You can see it here
I don't have any SU paper so I can't really say much about that, but I've had great luck with some other thicker papers.
I love the ability to use almost any font and have amassed a huge collection.
The files you can buy from the store are economical and cover a huge range of styles. You can download the software & play with it for free if you're worried about learning to use it.
And, yes, you can use it to "die cut" stamped images. I've seen at least one video on Youtube about doing it - but it looked super fiddly to me so I haven't tried it.
I don't think I will EVER regret this purchase. It rocks!