And I think it has reinvigorated his riff writing talents. The last three albums (ADTOE included) had some really forgettable riffs imo. I love the riffs on DT12 though.
I agree that ADTOE has some forgettable riffs, although I mostly feel the same about DT12. DT12 does have more good riffs than ADTOE, especially in IT (that 12/8 one is killer, and the first verse one is great too). Can't think of many others from the album though.
While those albums are still guitar heavy, I don't think they're as riff focused in the songwriting as the later MP albums were. They're not as metal oriented in style, so I think it's an intentional shift in songwriting.
Because of that, I think BCASL and SC were much better for riffs. SC in particular had plenty of memorable riffs across the album.
But JP doesn't have a bad album. Every album is going to have some cool new riffs and at least a couple of killer solos.
I like all the riffs in IT, they really hit it out of the park with that one, it rivals TGP for best riffs really. But I also like the riffs on The Enemy Inside (although I hated the riffs when I first heard it, seeing it live really helped me appreciate them more..it's explosive life
), The Looking Glass has a cool riff, and I really love the riffs on Enigma Machine, especially the main one. There's a lot of syncopation on DT12, which I really like. I get what you mean about the songs not being as riff focused, but I like that and I think it actually makes the riffs come out better.
BC&SL and SC have some great riffs, but some really bad ones too. I love the opening riff on Nightmare, the main riff on AROP (only salvageable part in the song IMO), and some stellar riffs on TCOT as well. Not much else sticks out to me, besides TSF but the best riffs on that are from TGP and This Dying Soul. There are better riffs on SC but unfortunately the songs as a whole are much weaker IMO. Which is what puts DT12 ahead here, it has great riffs and great songs I think. A lot of things felt arbitrary on BC&SL and (especially) SC, including the riffs, but on DT12 they seem much more natural and add more to the songs.