The advantages of this nuance are that the order can be reduced, and the disadvantage is that the warranty period will be reduced. You should also ask the quality of the reinforcing profile: the steel galvanized is good, and the usual metal is unstable to corrosion and has a low strength threshold. The inside of the profile is a hollow and consists of a large number of air chambers: it is better when there are many, because then the window will be warmer.