lucy24 - 1:18 am on Jun 24, 2011 (gmt 0)
The end result looks exactly the same to the browser or bot that made the initial request.
The 410 status code tells search engines to de-index the page.... You can continue showing content on that page to the visitors that continue to arrive.
OK, then we are in "at the whim of your server" territory, because once I've got a 410 in place, I can't see the page any more. Instead I got handed a server-default 410 that was even scarier than the server-default 404. (Scarier to ordinary humans, that is. Robots don't feel fear.) Past tense, because as soon as I discovered it, I physically rerouted them to my custom 404 page. Most people don't care about the niceties of whether a page used to exist or not, though the ones in the OP's situation might.