I bought and installed both the "Rental Upgrade Kit", and the "Tough Armour" kit from J.D. on my 4310.
One of the first major jobs I used the tractor for, was tearing down a 70 yr. old, cinderblock house that had collapsed under 5' of snow.
During this demoliltion job, I had a cinderblock filled with grout, roll off the back of the front loader and land on my nice new shiny plastic hood. I now have an 8" gash in the front top of the hood, repaired, but effectively covered by the, better late than never, tough armour guard.
I live in the mountains of Colorado and do a lot of brush hogging and excavating in areas that have big, sharp rocks that you can't always see until you are already on top of them. I think the skid plates will help save me some time and money over the long term. They seem to be fairly well made, and for me anyway, inexpensive insurance. The tough armour is also well made and I would recommend it to anyone who does a lot of loader work, especially if handling rocks.
If you order these kits be aware that the brush guards for the rops mounted hazard/turn signal lights, are not included, but are an extra item.
If you have any other questions, feel free to ask, and I'll try to answer the best I can.
DT