Rangers is right. The amount of memory is THE factor when it comes to Average Joe. I work in a certain country where less than 0.5% of PC owners know what they are buying. They just go for the big numbers, and 512MB and 1GB sure sound great. They think that's where the performance lies. (And who could blame them with all the numbering, Xs Ts)
How many of these average joe's are going to be buying a £400 graphics card? When it comes to enthusiast parts it is more to do with performance, as most of these people are technical and know that more memory doesnt necessarily equal more speed.
As for my case, from the bracket to the end of the hard drive enclosure in the front, which has a big thick fan on it as well I get around 14 inches, probably be 16 inches with just a plain hard drive instead on an enclosure. Besides, anyone buying this card who has a small cheap case deserves whats coming to them