I was not there but i believe christian(xxSVxx) lost a bolt or 2, and bent the skid back, also his skids are prototype skids from a friend of his, so not the same as the hefty versions.
Aluminum vs steel has it + and -, + is they are lighter, - is they are more prone to gouging if sliding over rocks with the full weight of the vehicle on them and they cost more than steel.
If you are just doing casual offroad, aluminum could be a good alternative if the additional cost is ok