Do you use Svbtle or Radio2? Why?

I know, I am comparing apples to oranges, because Svbtle is a closed network and Radio2 is more like an open protocol. But both have some visual and user similarities in that they are very simple, very straight forward compared to some other solution. Yes, even simpler than Tumblr or Twitter.

So: why does one want to use Svblte or Radio2? Let me know your