SoI sounds unbelievably contrived with its polished sound - but are we really surprised if they hire bland producers like Paul Epworth and Ryan Tedder?
Everything that is wrong with that record is epitomised in the recording of California - take notice of that horrible crass synth running through it. That desperate need to have a contemporary sound results in the musical equivalent of fake smiles and botox to desperately appeal to a certain audience.
U2 are at their best in my opinion when their music encapsulates a sonic world which conjures up great imagery - ala The Unforgettable Fire. As Brian Eno said, he likes his music to be imaginative which conjures up 'a film of some kind'. Naturally then, this requires much sonic experimentation and we probably have to accept that this will not be the case for Songs of Experience. As such, with the straight forward conventional pop song structures they created on Songs of Innocence, it is only right then that its follow up should take into account the errors of that album and give us a live muscular sound. If they had done so with Songs of Innocence, I would have probably been much happier with it than the soulless mainstream pop sheen they desperately applied to it.
A message to U2 - you aren't Coldplay, you aren't Imagine Dragons and you certainly aren't One Republic. You are way way better than that, so STOP bringing yourselves down to their tawdry levels!