Seems to me like that most of the elements are in place - city you want to be in, work you can do, significant pay upgrade, and crucially, a positive relationship with your direct manager. If you're young in your life (as well career) the truth is you can afford a greater degree of risk - worst case scenario here is that you get bored in 6-12 months and then maybe look again; best case scenario might actually be the same thing.
I'd take the job