i have it on my front end. at a 5mph collision, my car bounced back 4 feet or so from parked (friends mom backed into it)
im still running it, just bent it back into shape and had my bumper repainted. id do it again if given the choice. 25 lbs of weight on the fronn end makes your turn-in much better. id keeep it on the rear though. stupid people are always wanting to poke my arse. and i can stop much better than pretty much anything on the street, so im figureing ill stop and get smashed from behind more than ill hit somone.