I checked with my sources(Another KnifeKnut), and discovered that the 840 was called the Ascent by Benchmade. They have recently updated their Ascent line of knives so I don't know if it is still around.
(Thanks Ouch for the info)
Actually, if you are talking about the version that had the round hole like the AFCK, I have had experience with it. I purchased a couple of them, but had some problems with blade action and rubbing. They are good utility knives, and right now if you find the right one that has none of the rubbing or centering problems, they will do you well. I particularly liked the SBT versions.
If you have one and like it, carry it, use it in good health!!