From my personal experience, I have received a couple of offers through Dan.com's search, but I'd lean more towards that was more luck than by design since those offers came when I wasn't actively using their landing pages. Otherwise, it's going to be mostly type-in traffic. Hopefully that'll change more as they expand their Open Domain Distribution Network to more partners, but that will take some time.
I think the 9% is worth it if you don't want to create your own landing pages from scratch, need a easy-to-use CRM, and want a buyer to have an easy experience to get your name. It's even better if you submit your own leads/transactions to them for 5% instead if you already have a good setup to collect your own leads. If you're worried about the commission, just factor it in to what you are willing to sell your domain name for. The negatives I'd say about hosting on their landing pages is you may have to filter some bots if you are going to use Google Analytics.