I don't use spotify. But you're right, your playlist has a lot in common of what I like.

I usually use http://www.jango.com which allows me to create my own radio station by specifying a few artist names, and it will play tracks similar in taste to those artists. I know there are other sites like that, but I'm not sure if spotify has a similar feature. The thing is I don't like playing a fixed playlist over and over, I prefer things being a bit more random, although following the same taste.