Although I have a Silpat, I never use it for bread. It's too slick and smooth and I don't get the crust I like. So when I found out that the Silpat folks had a mat made specifically for bread, I figured it was worth a try. The difference is that the Silpain ($17.99) is a fine mesh mat, so there's air circulation under the loaf.
Does it make a difference? To give it a test, I made one batch of dough, split it in half, formed two loaves, and put one on a baking pan with the Silpain and the other on a baking pan with parchment. And I ended up with loaves of bread that were anything but identical.
I expected the bottom of the loaf baked on the Silpain to be a little crisper than the loaf baked on parchment, but what I thought was interesting was that I got a little more oven spring from the Silpain loaf as well, perhaps because of the dark surface.
The other benefit of the Silpain is that it's easy to slide the whole thing off the baking pan and onto a cooling rack. It's easy enough to lift a loaf of bread to move it a rack, but a full pan of hot buns isn't as easy. And since the Silpain has holes, the buns don't end up with soggy bottoms, so they can stay on the mat until they're cool enough to move them.
This certainly isn't an essential kitchen item, but I like having a lot of different options for baking bread so I get different results. Sometimes I want the crunch of cornmeal on the bottom a loaf, but now that I've got this mat, I won't be using nearly as much parchment paper.
The product was supplied for the purpose of a review on Serious Eats; this was previously published on Serious Eats.