Looks like the both the Pioneer (which is from the same stable as Onkyo nowadays, right?) and the Yamaha can go to 7.2.4, but only with an additional stereo power amp, so no different from my Marantz 7010 or its Denon cousin.
Although some say the Marantz is more music-friendly, I think it's only going to be a very very slight difference, so, honestly, I would go for the one you like the look of best and / or which you can get the best deal on. There really won't be that much to choose between them.