Personally, I think the bag guards and sliders make it easier for the bike to roll over farther when dropped at low speeds -- and that leads to broken mirror stays and crunched fairings.
Don't get 'em.
Well, I can personally vouch for having T-rex guards. I did a tip over coming to a quick stop on a banked downhill right turn. I went to put my foot down on the right and nothing was there. The bike went over and the wife got tossed over the guard rail. The only damage was my pride and some light scratches on the edge of the windscreen which hit the guard rail. The mirrors were not even close to the ground.
They were worth every penny that I paid for them just in that one instance.
Dave