ebay bidding agents

Something happened to me today that's never happened before.. of course I don't buy stuff off of ebay often...

I was outbid on an auction, which I theoretically don't mind because I try to restrain myself and really stick to my maximum bid. But I was outbid by two different people, both of whose bids were placed less than 10 seconds before the end of the auction. Obviously this was the work of a bidding agent of some kind.

So, have you ever used one of these? Which ones are good? Which ones are NOT recommended?

http://www.auctionstealer.com/ is the best recommedation I can pass along from an expert.

I snipe people in the last 10 seconds the old-fashioned way: manually.