The sad fact about Radiohead is that they've barely made a memorable track since OK Computer. Which was almost 20 years ago. And the few that do stand out, e.g. Everything in its Right Place and Reckoner, are mostly just good for the first 30 seconds before getting boring. They don't really have it in them to write great melodies, so they compensate by layering tons of 'complexity' and conceptual experimentation onto the records (and their career in general).
I remember when Coldplay's Parachutes came out, Radiohead fans recommended it to me. I thought it was pretty good. Then when Rush of Blood to the Head came out and cemented their popularity, Radiohead fans simultaneously dismissed them as rubbish and called them a Radiohead clone. Strange that. In reality, the only thing they had in common was high quality production (remember, the 90s were dominated by pub-rock) and falsetto singing. Coldplay had hits in them, Radiohead by this point just had critical acclaim (the general awfulness of chart music between 1998 and 2002 led some poor rock fans to spurn anything catchy-sounding in favour of shoe-gazing nonsense).
I remember the long anticipated day Kid A came out (and some ridiculous thing about them recording two albums simultaneously and only releasing one at a time, and how if you played 2 copies of Kid A 15 seconds apart then it unlocked a whole new experience), asking Radiohead fans if they liked it, was it better than Bends/OK, what were the best tracks. They all said something like 'not sure, it needs time to sink in.' 'I won't know if I like it until I listen to a few more times.' Thing is, basically anything grows on you if you listen to it a few times. That's why mediocre bands manage to do 2 hour concerts for their fans, when the rest of us only care about a couple of their songs. The true test is how much of an impression it makes at first.
Curiously I don't think I ever bought Rush of Blood to the Head, though I obviously enjoyed the singles. Coldplay in my book were a good band among a number of other good bands (Travis, Franz Ferdinand, The Libertines, etc). I did buy X&Y however, and was pretty impressed - they'd managed to get past the '3rd album' curse that most bands stumble at. When Viva La Vida came out, I realised that they were starting to pull away from the pack - they weren't 'cool,' didn't have critical acclaim, but at the same time no one could name any other bands which had released 4 strong albums since 2000 with amazing singles on each one. And they were now the biggest band in the world. With Mxyo Lotto (or whatever it's called), they came up with possibly their best single yet (Charlie Brown) and the others were great too. They now clearly deserved to be the biggest band in the world.
With Ghost Stories they have pulled it off once more. At this point they are in a league of their own for bands active since 2000. In historical terms, I'm surprised to say it but they're actually catching up with Oasis. It's doubtful that anyone will ever match the intense brilliance of Oasis's first 2/3 years, but slow and steady wins the race as they say. They have probably surpassed Blur. Their legacy is pretty secure at this point - a large list of anthemic hits and great album tracks. And the best thing is, there's no reason why they can't keep going.
Criticisms of the album? It's quite short, although I don't have the two extra tracks. Also I'd like more sections for some of the songs, e.g. Magic, Sky Full of Stars.