This.
OMG are crushing live, because it's the heaviest side of Isis and can stay focused in a coherent set list where they play the hits. But, man, the albums just wander all over the place. Same with Sumac.
The genius of Isis was having guys in the band that had strong enough personalities and their own writing chops to reign in Aaron Turner. Left to his own devices (and apparently in OMG too) he just can't keep songs focused enough to produce a great album all the way through.
On the other hand Palms, which is all of Isis excluding Aaron, + Chino Moreno on vocals, is too soft. The songs are constructed more better than OMG or Sumac, but they lack the Aggressive Turner OverdriveTM.
Isis was pure synergy.
True story: back in 2002 or so I went to see Cult of Luna open for Isis on the Oceanic tour. It's beyond me why now but, while I had heard Oceanic, I preferred CUL up until that point.
For whatever reason CUL didn't really pull it off that night. But holy shit, seeing Isis was a revelation. They even leapfrogged Neurosis in my book. Although, these days Neurosis still remain the band to beat in the post metal space.