Personally I find them "muddy" no matter what or how much gain you are using? Also, & this is just my opinion, I think P-rails were a much better idea on paper than in real world situations. They do sound alright in some guitars & awful in others, I guess this could be a materials type of thing? They def. do not work well in darker sounding guitars, so if you want to use them & act. like them drop them into a fairly bright guitar & the "Phatness" of the P-rail will help the signal sound clearer instead of hurting & muddying it up. Again, just an opinion, some guys love them! They wouldn't still be making them if not? That being said I don't know how many of my friends including myself have bought these thinking they were the answer to all our prayers & much to our disappointment we were left wanting? The good thing about them is there are always tons of used sets on eBay so if you want to try them you can do so without spending almost $200, then again if you spend "NEW" money you can exchange them for something else through Duncan even if your dealer will not honor their exchange policy, 99% of them will but buying off the net can be a P.I.A.?