Is there any harm setting Gamma to 1.8 on new iMac retina?

[snerkler]

I do a lot of photography and when I first got my iMac retina all my previous photos looked very dark, with almost too much contrast too. I calibrated it using an i1 display pro and it improved things a little, but not by much. I've now just done my first lot of editing and found that when I edited them by eye then they looked quite overexposed when I viewed on my iphone, iPad and Macbook, and the histogram confirmed this. I played about with the calibrator and found that setting Gamma to 1.8 rather than the suggested native 2.2 made the images look much more like I'm used to, looked better across my devices and using the histogram.

I was going to leave it set to 1.8, but before I do is there any harm in doing so, ie is it going to display wrongly somehow?

Any advice appreciated.