I would think that at the size of my bench that finding glass could be a problem. Also with leveling screws in a laminate top it can be leveled fairly easy. I've built several wings on shelving material from home centers, easy cleanup. I even drilled holes in one and used 90 degree brackets to hold the ribs vertical while the glue dried. For now I build without a jig, although I do have access to one(Adjusto jig), but haven't used it.
Steve