Very causal PJ fan here. Gave it a listen, didn't seem like a very adventurous mix (only listened to the core 5.1, to be fair).
There's pretty much nothing in the center channel, the rears usually get vocal and synth reverb and some guitars. There are some fun moments like Good and Evil and Rose of Jericho where I could hear some discrete guitars in the rears. The first track also sounds very spacious with the reverb fed to the back. At other times though, it sounds like big stereo.
Wasn't very impressed with the album on first listen, especially the second half which had a share of downright embarrassing tunes that almost had me reaching for the remote (Try and the EJ duet). Much prefer Gigaton, album and mix-wise.