I just installed the bumper and lower grille lights today and im going to have to say they are amazing. My old truck had them on the roof and the only difference i can think of are these. (Please correct me if i am wrong)
Bumper
Pros
Easy install, briter than you could believe, makes the headlights not even worth useing. This set up is ideal for good cruises through the woods and stuff but not race style, great for hunting.
Cons
Light in bumper may cause excessive heat, and could possiblly render some air flow into the radiator. lower grille- If you are planning on haulin ass field of view is very important. The faster you go the quicker you pass by the light. So lower grille (if you havn't replaced your bumper) would be pointless in race style conditions.
Roof rack
Pros
Keeps your bumper "clutter free" while keeping high ammount of light in front of you. It gives you many options for driving, applicable for all conditions
Cons
Sounds could become a bit irritating at times (but those times who is paying attention) maybe slight wind rattle at higher speeds. not sure though bc i havn't ridden in a raptor with the roof lights yet.
Also mention'd above is the possibilitie of not being able to use your sunroof. This is not the case on all racks but def something to be worried about.
Hope that helps.
After installing the lower and upper bumper today i am really impressed with the light output and also, we did not want to add more to the facia to the truck at this time so the hidden light behind the bumper was ideal.
Good luck with your choice