The experience was pretty awesome. The sign up was easy, and I was up and running doing posts/replies to questions. Watching the reaction to the conversation was pretty cool.
The next interview/conversation I have on my personal blog, I'd like to use ReplyAll simply because it helps in creating the most insightful comments/responses. If you were to do a conversation real time (podcast/phone/live), a lot of thought is lost while thinking on your feet (you can be really good, but it's likely inchoate relative to the true potential while you're writing and thinking). On the other hand, if you're doing an "email interview" where you just have a long set of questions, there's no freedom to let the conversation go as it should without some heavy editing.
Cool product, well done Zach, et al!