I hear you on the slippery of the melamine. I guess it's 6 for one and a
1/2 dozen for the other. You wax the bottom of plywood and I use stick-on
sandpaper for the top of melamine. In other words, you start with grip
work for stick, and I'm vise versa.

OK

As for strength, it's really a moot point in this application.

My point was more about weight than anything else. My big sled probably
weighs in over 15 lbs ... it's just awkward. But, I'm all about "free" too.

However, I already made my own out of hardwood and found them to be
superior to the factory made ones, and very easy to make from shop scraps,
which are "free."

You either have better skills or better hardwood that I have. IME maple
works fine for dual runner sleds but it's either seasonally sticky or sloppy
in a single-runner application. Your milage apparenty varies.

Cheers,

Steve