I bought the adventure spec engine guard , because I thought they offered the best protection.

That said I wanted total protection for under the engine when off road riding and I felt that the Adv spe guard had a few Gap's in it that needed filling to prevent any chance of the cases being damaged.

I can't see these low snug fitting engine bar's being a problem, you tend to find that crash bar's that are mounted higher can cause more damage if you throw your bike down the road.