Who told you that? The old school Lanzar was good (back when the Opti's were Zed Audio built), but I wouldn't exactly call most of the new Lanzar stuff "quality", and definitely wouldn't say the "excel" in that department. They are pretty much an all out budget brand now. I kinda consider them to be the higher end of the low end.Both are well known manufacturures but lack in the advertising department but excel in the quality of their products.
are you sure the frame is made of plastic? i dont think even the cheapest subs have plastic holding them together, it might be metal coated with som kina plastic. just nitpicking, hope they work out for you, how much did you pay if i may ask?