The value-add they offer is good, but I'm never gonna find out about it first hand because I'm not gonna pay to try it (even with a 30 day money-back guarantee)
I predict they would have far more luck if they open-sourced the basic library (so we could use it to get say 80% of the functionality ourselves BUT would need to self-host it etc. etc.) and then offered a hosted version for $$ per month.
Good luck!