9mtg: See if you can understand this:
Logic 7 on the Lexicon DC-1, DC-2, MC-1, and MC-12 processors can be applied to stereo and 5.1 DD/DTS (and by definition, DD EX and DTS-ES matrix) formats. Maybe even DD 4.0 for example.
On the cheaper H/K receivers, you can only engage Logic 7 on 2 channel stereo sources. Then why do they call it Logic 7 for 5.1 or 7.1 channels? Because that's what it "expands" the 2 channel stereo source to. You gave to go up to the 7000 (I think) before you can get Logic 7 on an H/K receiver that can be applied to a 5.1 source.
The new 225 is *rumored* to have Logic 7 able to be applied to 5.1 sources. (I saw a blurb in S&V mag on it.) So the presumption is that will also be the case for the 325 and 525 when they come out.
Make sense?
This all kinda sorta has already been covered, more than once btw, on HTF...