I think I am one of the VERY few in here with bullbars, I notice nobody is really a fan of these things in here but me.
I did have an incident where I was trying to turn around and look at my baby in the car seat once at a stop light and I accidently let go of the brake and the momentum made me tap the car in front of me. It was enough to push the bars back or upwards since there was enough give in it. I presume this was good at the time since I didn't SUPER tighten it to the max. Maybe that is a good idea to do that but in the end I tried to tighten it more so it won't push up easily.
The vehicle I hit was a slightly old mini-van with a normal wear and tear bumper. The other driver just asked if my baby was okay and we just went on our way. They were pretty nice about it even though it was a pretty hard tap or bump I felt.
Of course I scuffed up the bullbar and just repainted lower bar black.
Moreover, nobody has hit my front bumper in the parking lot anymore. I only installed this bullbar because somebody hit my front bumper and chipped the paint and broke my license plate cover. So I had a good reason back in the day.
As for the installation, it's really easy but you just have to trim the bottom plastic cover which is really not that hard. And you end up replacing some radiator bolt with a longer one that is used to anchor the attachments for the bullbar. I vaguely remember something like that and yah it doesn't sound good huh? LOL
But I don't see any problems in a mid-level city where you have a less chance of hitting something unlike a major busy metropolitan where there might be alot of traffic, cabs, buses, people all over the place where accidents can happen more often.
The only damage during mounting is the plastic underside cover and the reason I bought black is that I can easy paint them; and if they rust I can use some rust converter and it will be a black primer. Unlike chrome, I was going for a more understated look and not as showy. Which is why from afar if you're not really looking you can hardly notice the nerfbars or bullbar at times since my vehicle is kinda dark also.
So yah, mainly for parking lot protection and decorative purposes. Since the Rogue is one of the least modifiable vehicle visually. Yes you can tweak a little something here or there but other than that most Rogues out there could just be any other Rogue from the NIssan Website. Everybody's Rogue actually looks the same but a different color.
Especially in my area, now that the Rogue has been around for 3-4 years it has become more prevalent. I see one everyday and a few in my neighborhood. But at least my Rogue stands out more with the bullbar and the little tweaks here and there that makes it oh so slightly different!

ps- I actually removed the plasti-dip on the emblem and raised the bullbar a few millimenters since then.