My PFR is at around 10.5% for the last approx. 15k hands, and I still find a few places where I'm wimping out and not raising more marginal hands, particularly at tables with tight players to my left. When I started out at 0.5/1 and lower, my PFR was around 7-8% after reading SSHE, so I think that's a good starting point. I'm finding that more and more my raises are situational, blind steals/iso-raising weak limpers and LAGs, etc. It can occasionally put you in some tough spots post-flop though.