I'm just wondering whether anybody has listened to both the 640SE and the new 757SE?? Can anyone tell me whether there is a huge difference in sound quality / processing ability between the two? I have the 640SE and can't decide whether it is worth upgrading yet? I know these things get better and cheaper all the time, but the recent changes in the market seem unbelievable. For example, the Pioneer 1015 seems awesome value for money (THX etc). It just seems like over the last 6 months things have just gone daft. Not so long back I was looking at the Denon 2805 at £500 ish - but now Pioneer have released the 1015, and Yamaha fight back with the 757. These units seem dirt cheap.