Yes, unfortunately that's what I'm hearing as well. I voted a 7 for those exact same reasons. When that first guitar solo in "Splintering Heart" comes in, it's like all the life is suddenly sucked out of the track. I remember experiencing something eerily similar with the 5.1 mix of Opeth's Heritage album, the quiet passages sounded fabulous while the louder bits seemed oversaturated and lifeless.I'm having some issues with room correction so I'm not sure if what I'm hearing is just my EQ or a real issue. I'm noticing that the quieter bits sound great but louder parts not so much. For example, Splintering Heart sounds great but when I'm really anticipating the crashing guitar solos, they sound... compressed? Like everything gets squashed together and the hi-hats and crash cymbals are fighting with the guitars for centre stage. I listened to Closure/Continuation in Atmos after and don't find this issue so maybe it is the mix? Does anyone else notice this? I find this in most of the songs.
I agree with you on the vocals sometimes getting lost as well, perhaps because there's so much higher-frequency information mixed to the back (stuff like synths, rhythm guitar, backing vocals). I'm willing to accept that the issue may partly be system-dependent (I'm seated fairly close to the rear speakers), but when the choruses in "Cover My Eyes" and "No One Can" come around I'm hearing like 70% backing vocals and 30% lead vocal.