Hasta La Motion!

I was reading many of the post talking about gamma and exr files, and I got a doubt:

Somebody says that rendering in 2.2 gamma in exr files is bad bad bad. Some replies later, somebody else says that, If you don’t get the desired result you can put a grade and that’s all. (that was I was doing, till now)

Is it incorrect? Is it affecting the final result?

I didn’t try it yet, but I think I would reach the same result (moreless) without rendering in gamma and play with the shadows and occlusion pass… …
Would it be better?

Thank to all help.