If anything, The Eraser is pretty underrated. It is an awesome album that got better with time and some songs, like The Eraser, Cymbal Rush, Analyse and Black Swan are on pair with some of the best Radiohead songs. IMO The Eraser has some of Thom's best lyrics as well.
Thom IS a genius musician, him liking being called it or not. His work with Radiohead is proof of it, as well his solo work and his work with other musicians (how unfair it is to ignore his many collaborations with other artists. His singing on songs with Unkle, Bjork, PJ Harvey alone are better than most artists could ask for on an entire career. His work on the Velvet Goldmine soundtrack is brilliant, and let's not even start with the Modeselektor and Burial tracks).
So, taking in account what Thom did until now, to come and say that Ed might make a better album than The Eraser is something I can't even conceive... for real, WHAT did Ed ever do to make someone think that? Backing Vocals? Really? Ed is a great musician, I have no doubts about that (all of them are), but he, probably, would be the first to admit he has nothing near the talent Thom and Jonny have. These two are on a different league. Jonny's classical talent is amazing. It was always there and it would be a shame do not let him develop it though his orchestral work and movie scores. And Thom is a singer/songwriter since he was born. If not for his ambition on being a rockstar as a child, playing and writing lyrics like crazy, we wouldn't have Radiohead. He is a natural singer, anyone can see that he is a complete person when he is in his front man role on stage.
And, let's note, both Thom and Jonny bring these elements together in Radiohead. Do you see Phil adding something to Radiohead through his solo music? OK, no. And I see the same happening with Ed solo. They won't add anything to Radiohead, on the contrary, it might disperse their attention to the band and make the end comes faster than would naturally come if they still focused in doing what they do best as a group.
yeah, I know, not a very fan friendly opinion but... whatever. I wouldn't support Thom if he decided to become an actor or a politician either. Phil trying to pose as an VERY awkward frontman and Ed going solo are comparable to that, IMO.