I have the RX-V671, which is not one of the items. However, the Amazon review of the RX-V571 shows that the V571 is similar to the V671, less some features that I don't use. So, they are functionally similar.
The YPAO device is very nice. It allows you adjust the energy from the speakers to allow balanced room-filling sound. I did decrease the front center channel and increase the front L/R, because I have a pair of nice tower speakers that give great bass response. Other than that, the automatic balance has been great.
I live in a shotgun-shack house, where the living room is a 25' wide by 40' long box. Having the 7 speakers allows me to put the rear speakers at the far end of the room, where my computer lives. So, I can play music or TV at a low level and still hear it while at the computer. I haven't found a ton of greatness for movies at 7.1 rather than 5.1, but managing softness is great. For big rooms, get the 7.1 for that reason.
Oh, and the sound programs? I tend to use the vanilla 7-channel setting, but sometimes I like bassy music sounds. As I mentioned before, I've boosted the levels to the big front towers. I can therefore pump out a LOT of sound from the 7 speakers in the club sound modes without a lot of distortion.
I like that I can re-program the front buttons to say what the actual setting is (XBOX instead of CD). And having a fool-proof button on front to set the box for the TV is wonderful for my wife. ;-) I just wish it were the left-most button rather than the 2nd; I rarely use Blu-Ray, so finding button 2 is mildly annoying.
Finally, I note that the review linked above shows the difference between the V471 and V571. The big difference is the video up-conversion. You'll miss that, IMO.
I like my V671. Maybe you can tell.