I have made the switch from the soon to be defunct Posterous, to the new Post Haven blog hosting service for my personal blog.
I was somewhat reluctant to move at first, when you are getting a great service for free, there is a certain amount of inertia to overcome in making the switch to a paid service. Don't get me wrong, I believe in paying people for their work. However, when you have been getting something free for years, it takes a certain amount of mental gymnastics to make the switch to a paid service. (hey, I am talking BLOGS here ok?) :)
It is also not always successful. As twitter has changed (and not for the better) I tried really hard to like the paid alternative service, app.net. I paid for an app.net account, and tried to make some new relationships in that paid alternative to twitter, but it just did not work for me. App.net seems to be a very closed club of developer types that have their own cultural reality, it just did not replace twitter for me. So, despite all the things I DONT LIKE about twitter, (including cutting out APIs and third party developers, sponsored ad tweets, changes to the format, etc), I still use Twitter.
However, I think I am going to have a very different reaction to my switch from Posterous to Posthaven. The import of my Posterous blog seems to have gone without a hitch. Everything moved, even the comments. I am looking forward to all the features that the developers are committed to adding to this service, and growing my blog with them as they continue to refine and improve their interface. I really like the idea that even if I quit paying for the editing service, the blog archive STAYS UP, and I can start paying again anytime I need to edit.
I don't have the time, energy, or patience for Wordpress. I want and need a KISS principle blogging platform. While $60/year is a fair amount of scratch in internet terms, I think I may be here for a while!