Domain Names (much like anything else at auction) put pressure on a potential buyer to put in their offer if they want a shot at the name, especially if the domain name has surpassed the reserve.
My last sedo transaction, I chose not to go to auction out of respect for the buyer offer, which was more than I hoped for the name.
I liked the auction. It is good at controlling the quality of auction name. I hope they won't introduce something like you can pay a fees to go into the auction system Like Featured Names at their homepage which contains so much rubbish.