EZ-set is not nearly as advanced as YPAO is...though I do think it's a great feature that most receivers should have had a couple of years ago.
In addition to setting the speaker volume levels, YPAO adjusts the delays for speaker distances, tests the speaker's size (ie: small or large) and then optimizes each speaker’s frequency response using a parametric equalizer.
It helps compensate for room imperfections and tries to balance the tonal qualities of all speakers.
This doesn't make your receiver obsolete or anything, and with a bit of work during setup, you can accomplish many of these features manually.
YPAO is actually a feature that can substantially improve the sound quality of your system, unlike alot features in today's A/V receivers that you may or may not need or use.

Pioneer and Denon seem to have comparable systems in their newer receivers, and I expect everyone else will follow this trend. But hey, we all got along just great for years without parametric equalization and other big fancy words, so don't sweat it... you've got a great unit and saved yourself alot of money to boot!!! Enjoy the H/K!