These are the tires I have on my truck right now,

http://www.mastercrafttires.com/us/en/ProductDetails.asp?ProdType=LtTruck&id=85

I know they're by no means great but I'm hoping some of you tire experts can tell me if they are Ok for offroad conditions or worthless or whatever. I've done quite a bit of offroading and they've served me fairly well but I often feel like better tires would make the experience better. Basically I'm wondering if I should think about spending the $500 or so on new ones when these only have about 5000 miles on them. Can you guys analyze the tread pattern at all?

Thanks in advance.