rofl
Tactics Trainer
I was hovering around 1600, but I've slowly dropped off to ~1400 when I started doing them more regularly. I'm not sure that's the way it should work. 
I wasn't far off 2400 but have dropped off to 2200 now... I don't think I'm very strong tactically but once you start to learn what to look out for in tactics trainer you can get a decent rating.
I used to drift between the 1200s and 1300s, but I changed my strategy. Now I take as much time as I need until I see the tactic. Initially when I did that, my rating went down, but now it is in the 1600's. I think doing them slowly helped learn and then I started seeing the tactics better.
Just a theory.

Just wondering what your rating is? I think mine is around 1250 only now:|