I would have to check to make certain, but I think the only album I bought in 2015 that was actually released in 2015 was "Hand. Cannot. Erase." by Steven Wilson. I bought a shitload of music last year, but most of it was older, some much older.

I heard "Rattle That Lock"" and it was probably my biggest disappointment of the year, especially after the unexpected joy of "The Endless River". RTL is not actually bad, just rather ordinary.

As for "Head Full of Dreams", it's not exactly a disappointment because I have learned not to expect to be blown away by a new Coldplay release. I thought Viva la Vida etc. was a brilliant album. Every album since then seems to have been trying unsuccessfully to recapture that magic.