Paid members (yes I am) don't get ads so don't get all that space lost to advertising. You didn't hear this from me, but plugins for Firefox like AdBlocker and FlashBlocker will reclaim that space (to an extent) because it doesn't display the ads.
As a full-time web-designer by day I welcome the overall upgrade. As people are saying - a change is disorientating and some things - esp. search - still need some work (As does the letterspacing in the logo but that's another issue altogether) but we'll all get used to it. I think it's a shame a change in format is enough to alienate users to the point of not participating anymore. It's the message not the medium right kids?