I have the factory yamaha aluminium skids, not tried anything else but regular steel skid plates on trucks.
Saved a control arm already from an hidden rock in tall grass.
For the looks, IMO they can't be beat. They also protect well the areas they protect, and prepare 2-3 hours to mount them for the first time.
I'd venture to say that 10MM HDPE will protect more than the approx 0.1" thick AL skid plates, but they might fail easier in the attachment areas under a large front impactt, but that is just an estimation. They also protect the underneath of the foot wells where the yamaha aluminum ones don't

. already had to fiberglass repair a foot well due to a big rock tearing the back of it. I don't know, though, if the other set would have saved it.
Yamaha pros: looks good
lighter than the 35-53 lbs of the HDPE set
yamaha cons: high price $$$$
no protection under foot wells.
I LOVE the look of the OEM yamaha but if I were to do it again, I'd go for the 10MM HDPE