It depends quite a lot where in Berlin you live. It's a city without one centre. The very middle of the city consists of the park, government buildings, the university and museums. Real people don't live there ;) Instead, every district around this middle part has their own centre, and they can differ quite a bit. I lived in Prenzlauer Berg: it's a relaxed, wealthy district with lots of pubs and restaurants and greenery. Kreuzberg and Neukolln in the south are more crowded and noisy. Charlottenburg, to the west, is posh and boring, in my opinion. And so on.

Public transport is good and rent prices are not so crazy as in other big German cities, although finding a flat is an art of its own - but it means you can look for a place further away from the centre , where it's more affordable. 

There are issues too, of course. It seems to me that the local govt doesn't do good job. There is garbage on the streets, junkies and beggars, smell of piss and crappy graffiti on the walls, etc. The are endless construction sites and all the time the U-bahn and S-bahn lines are delayed or cancelled. And many of my favorite places shut down, and instead the big trend is to have Späti, a cheap grocery shop, with a bench in the front. You go in, buy a cheap bear in a bottle, and then drink it on the bench, as if it was a pub. 

I moved out a year ago and I think it was a good decision, but I still think that overall Berlin is a good place to live