I've not sold any, but I've bought one (the name in my sig actually). I realise that probably isn't too helpful for you, but I've spent a while in the auctions and based on that I can tell you that names with PageRank (especially 3+) will do extremely well. It's more of a global .com/.org/.net marketplace.
Also, watch out for tons of added hidden costs heaped up on top. I know buyers get silly costs added, so I wouldn't be surprised if they charged you a selling fee or something after a domain's been sold.
Worth having a google around for discount codes as well, I know they occasionally have codes for free auction membership, same may be true for listings?