Many distributors will give you a sheet of material to try. Most manufacturers will give the distributors allowances for this. You must also look at your tooling and the differences in core material. Southern cores tend to be harder on tooling than western cores. Then you also have to look at the differences between western pine and western fir.
Warranties are also something to look at.
Panolam is the only company I know of that will put in writing that their melamine will meet NEMA standards for wear, stain reistance, etc. It meets or exceeds all NEMA standards for vertical-grade laminate. As far as comparisons on paper, there are none that I know of. I used to sell melamine, machines, and other products to the woodworking industry. I found that a shop that was looking for the cheapest product didn't care what it was.