Ask YC: Anyone used Hubspot?

My web-based startup wants to work on its SEO and inbound marketing. In other words, pulling in visitors, and driving visitors to subscribe.

Hubspot seeks to help websites with these sorts of things through SEO tools, lead tracking, and analytics. It isn't cheap, but if it really works, then the price is worthwhile.

Has anyone here used Hubspot? What sort of experience have you had with it?