when saving directly to EXR there is actually no difference between the RGB channel and the Unclamped Color renderelement. Anyways...there simply are no AA issues with float...there are AA issues with values above 1. And even without using values above one float is a life saver. Not only for DOF...try grading 8Bit images for example. The adjustable range is so incredibly bigger. Also when working with layering in post it gives a lot more options as to the final look without re-rendering. Postprocessing is a VERY big part in our pipeline, and i never regret it comparing 3d-Output vs. Final Look 
Regards,
Thorsten

Regards,
Thorsten
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