Apologies if this has been posted before, came across it on a Facebook group.

Quantifying quality is difficult, but according to this study PN can reduce your quality of life by up to 32 %.

Haven't thought about it yet, but like many stats, they may not reveal the full picture, and/or may wildly differ amongst individuals.

Still: http://www.ncbi.nlm.nih.gov/pubmed/23716362/