Most of the receivers in my budget ~$400 used/new don't have Audyssey DSX, the ones that do only have 2EQ, no thanks. I have credit that I can buy brand new the 2313CI for 899, this is much more than I want to spend but it has both Multeq XT and DSX. I'm seriously considering just getting the 1712 from Denon used for 269, it has MultEq XT and then I can either use discrete 7.1 or PLIIz. I've never heard PLIIZ but plain old PLII doesn't sound good to me if the material is not already 5.1 and if their processing to matrix 7.1 into the fronts would be equivalent to what PLII does for 5.1 then I'd probably be disappointed (who knows maybe they do a better job). That said, many people that have tried the front wides with DSX seem to really be impressed with the upgrade. So I'm at a pitfall, settle for no DSX and buy a receiver that can do discrete or PLIIZ or break the bank with my credit line and go 899 with the 2313CI which I don't really want to do. Maybe there are alternatives, something in the middle. I'm sad to see Onkyo either has 2EQ and DSX on the entry/mid receivers then go to XT32 on their top end ones... I need something in the middle! Ha.
Edit: for what it's worth I'm just assuming Audyssey is the best auto calibration technology right now? I'm using a Yamaha that doesn't auto calibrate anything (I had to do this manually), it sounds good though. Are there other auto calibrations that are good and processing other than DSX/PLIIZ that can do front wides/heights as good or better? I'm up for anything.
as an FYI, you don't have to pay full msrp for Denon receivers. Call up Electronics-Expo, AV Science, and other authorized dealers and you should be able to get it much cheaper. If you are willing to go refurb you can get it for $549 from acessories4less, or a 3312ci for only $20 more.
unfortunately a lot of this is subjective so you may have to simply try different configs yourself and see how they sound to you. If you get a receiver with DSX then you have the option at least of trying the different varieties of 7ch layouts.
the step-down 2113ci doesn't have DSX but it does have PLIIz, so at least you can try that. And you still get MultEQ XT, networking, video scaling, etc.