I like it. It's challenging, but nothing wrong with that. Obviously, if you're expecting The Bends or OK Computer, you're going to be surprised and/or disappointed...
I need to listen some more, but so far 'challenging' isn't how I'd describe it... for now I'll go with 'more of the same'. Haven't been excited by any Radiohead albums since OK Computer and Kid A, both of which are over a decade old.
I wasn't sure at first but it has slowly seeped in and now I like it a lot. And I like that there's stuff that doesn't give you the 'quick fix' - that way of thinking has so embedded itself that we often dismiss e.g. an album if we don't like it straight away.
Having listened to it a lot now, I can't square it with snags's dismissive comment above in any way at all. And it's especially great over headphones.