yeah herculiner is just a do-it-yourself rhino lining, no idea of quality difference though. i'm guessing your referring to the stock painted bumpers when you say "both plastic bumpers". i had the chrome bumpers. i couldn't find anyone who had done this to the chrome bumpers before so i just took the same basic tips from the painted write ups. one thing: some might disagree, but after excessive sanding and scruffing of bumpers, there was hardly a physical difference. and condsidering this stuff sticks to everything (including my hands and bottom of feet for about 32 hours so far), i'm confident that the sanding portion of the chrome bumper prep is unecessary. i'd say with prep and coats you're looking at about 3 hours. this is minus the approx. 12 hours to let each coat harden. i've only put on one coat all around so far and it looks perfect minus 1 or two inconsistencies.