I tried, I really did, but I love Opeth for what they produce and what the produced with Heritage just wasn't an Opeth record for me.
Opeth are (for me) about epic, intricate metal; gentle melodic phrases juxtaposed with thunderous blastbeats and riffing; clean vocals alongside growling. Many people point to Damnation with contempt as it was their 'mellow' album, and I loved that, but I just don't love this faux-70's Prog album.
It is just too weak. The songs meander along, drifting seemingly aimlessly between pointless musical whifflings and, at best, light rocky riffs. They lack structure overall I feel, and the album also contains several songs that fall into the filler category, a complaint I couldnt level at any of their previous releases. The absence of growled vocals is a shame too - the worlds best death metal vocalist and he has decided he doesnt want to do death metal vocals any more

I won't even mention the jazz flute! Oh wait, I did...
There are redeeming moments, but too few and far between for me to really view this as an Opeth album at all, almost all of the trademark features are missing and it is like listening to a different band. My tastes tend towards the brutally heavy, and Opeth were the band that managed to absolutely nail the sweet spot in my musical taste, but Heritage missed the mark completely for me.
I think Åkerfeldt is concerned about the damage growling might do to his voice - it certainly sounded a little off at the RAH gig. Seeing the setlist for the forthcoming tour (that I have tickets for), there is not one growling track on there. Makes me wonder if the quantum shift in their sound is a response to that concern, but the direction they have taken is not for me.
What did you make of it, out of interest?