Here’s where I ended up when I posed myself the same question.
I am no blacksmith, and have never purchased tongs, or used commercial tongs, so have nothing to compare them to.
I find that this pair can hold to 3/16 to 1/2 inch stock without having to stretch my grip
I don't believe the serrations do anything, though the in line groove on the small jaw helps stabilize smaller stock when held straight out the jaws.
I find these tongs agreeable for making hooks and other small items that the stock changes in dimension and shape , good grip without having to switch tongs , and plenty of room for things to hang out the side.
I had posted my first pair of these and was advised to put the cross slot on the larger jaw. Advice taken and utilized, with good results.