When you say that eLife is "very rigorous," could you elaborate on what specific aspects of their review process or criteria you find particularly stringent, and how those compare to the review processes of Nature/Cell?
In Nature or Cell, I have sometimes seen 2-liners sent to authors as a review, or reviews where the reviewer clearly read the article for just 10 minutes before rushing an opinion.
I wish eLife doubled down on this and disclosed the reviewer names after e.g. a 2-year embargo. This would make reviews even better IMHO, more skin in the game.