You call sales on Avengers 'moribund', but they are still doing great relative to the rest of the Marvel line and relative to a lot of DC's output; and that kind of fatigue and lack of excitement comes with people getting 'used' to a writer on a franchise, it being less fresh. That's the whole point of shifting things around, after all. Bendis on X Men is going to be huge. A newly reorganized Avengers group is going to be huge. All of that will be huge for at least the first 6 months. At least.
Maybe it won't last, who knows. But by that same token we won't know where the DC line is at that point, so nothing is sure.
I guarantee you that a reorganization of the Avengers and X Men lines, with new spots for guys like Aaron, Hickman, Bendis, etc is going to sell and sell big.
These are buzz worthy writers that will be changing the style and status quo of their titles hugely, and that is giong to be noticed. Even Aaron on a nothing character like the Hulk lead to huge sales at the start. Schism, which was a reorganization of the Mutant line, has been selling very well, consistently, and I think this is going to be even bigger. Bendis is certainly a bigger name than either Aaron or Gillen.
There is no reason to undercut Marvel out of some misplaced loyalty to DC. I'm excited to see what comes after. I think Marvel is really going to be firing on all cylinders, as DC has been.