The Helicopter DLC is out for Arma 3 and it is looking quite good. Dslyecxi has made another video based on the changes from beta to release which is quite interesting:
The flight model was relased as a patch today and doesn't require the DLC so you can try it out yourself. I gave it a spin and found it vastly improved over Take On Helicopters. It was also good to find something else to use my X52 Pro with.
As for the DLC, I think its worth it if you are into flying. If not you can still enjoy the features from the DLC just not fly the two new helicopters.