If it were £5-10 maybe, but looking at Scan the difference is over £20, and that pushes it too much for just a media system IMO.
I'm looking at a HD2400Pro for my HTPC as soon as I can find a passive one which includes a low-profile back plate, either in the box, ready fitted or even to buy separately. The 7100GS that I've got in at the moment can't even display 1920x1200 in MCE without stuttering, let alone giving it any decoding to do on top of that (if it could).