My camper originally had a wrap around style, similar to that pictured. It was singularly ineffective in protecting my camper or the rear of the Cruiser
. IMHO the mesh needs to be angled down to deflect any stones towards the ground. Those flaps would help, but are perhaps too far forward and too narrow to be as effective as they could be. I'd consider mounting them out from the front of the tool box, with much wider flaps.
The aluminium chequer plate on that camper is certainly going to help, taking stone chips better than a painted surface.
An advantage of this over the frame style is that it wraps around and so doesn't affect turning circle, as with the spare front mounted the guard would be well forward. Having the wings bent back wiht flaps on the lower edge would be good I reckon.
I have a Stone Stomper, which is highly effective, though I still get rocks caught up on the sides of the camper, even though the Stone Stomper is the full width of the camper.