Technically there are differences. Old furnaces used tongs to hold the glass, that is why some suppliers will have clamp marks on them. Modern furnaces use a conveyor system to prevent that. As well better suppliers will supply a flat product with minimal waves in the glass. Trust me there are massive difference s on the finished product between suppliers.
If you are worried of spontaneous explosions of the glass get it heat soaked. This process should filter out any faulty pieces.