I had NP3 on an ORM Colt 1991, and didn't care for it. All the gunwriters describe it as a 'handsome battleship grey', but to me it looked an ugly yellow. It was very slick, which made weapon manipulation difficult with a smooth frontstrap. It is relatively soft for a metallic finish, and seemed to scratch easily. It is also very expensive compared to a good hard chrome job. Bottom line for me is I wouldn't do it again. If I needed a gun with a more durable, rust-resistant finish than blue I would probably go with hard chrome.