Which is better, baking steel or a pizza stone

Which is better for you, actually depends on what you are cooking. If properly preheated, you will not really get a bad result with either one. If you are getting a lot of take and bake pizzas, however, you will come across various styles, and perhaps you will even want to try your own at some point. In that case, I would recommend a stone, because stones are very versatile and also make fantastic bread.
If you are specializing in NY Style, that is when I would recommend a steel. Steels are excellent (again, proper preheating is absolutely critical) for NY Style because they transfer their heat very fast. This is important in the temperature range of about 500-600 degrees, because something that transfers its heat fast, gives much better oven spring, which makes for better pizza. Above or below that 500-600 degrees range, with NY Style or not, then steel is excellent but really has no advantage except slightly faster cooks over stones. Within the 500-600 range with NON NY Styles, your results will be similar–steel a little faster, but stones equal or better in final taste.
In the stone line, we have a 14.5″ round stone that is slightly thicker at 7/8″. It has wonderful thermal properties, but is a slightly smaller target than the 5-piece 15″ x 18″ rectangle, so a little less forgiving if you have a bad placement of your pizza.
As for the life of the product, steel is superior in case you drop them. People say steel is forever, and it is if properly cared for. Our stones, however, are made of cordierite, and although they cannot handle a drop on the floor like steel, they will not break under heat stress like most stones because cordierite have a very low coefficient of thermal expansion.