Spent a few weeks there working and know quite a few people who live and work there, I am sure many are happy but the ones I talk to can’t seem to wait to leave.
From my direct experience didnt seem an awful lot to do, city centre was quite dead, the Rhine is nice though with some good bars on the river bank, think it has stuggled since Berlin has been the capital again, now you really only have three major employers it seems.
It has the feel in bits of a German Milton Keynes (please don’t take offence if your are from MK) just had a feel of being new and artificial, not joined up or community based.
On the plus side huge ex-pat community so lots of people to meet and Cologne is nice!
Sorry and as I said was only there for a few weeks in Hotels so never really the best way to judge!