What do you think?

...you mean, Fiberglass? x_X?

Yes fiberglass can crack, but for gauntlets its a suitable material. Fiberglass is great for the kind of stuff we do, better and stronger than vaccume formed styrene and other plastics but by no means is it indestructible, it will crack under pressure.

I personally would rather have fiberglass armor over vaccum formed armor. Yes thats how the move armor was done but for trooping and what not the fiberglass would probable last longer under the wear and tear

Fiberglass gets much more strength when it is curved. That is why you see panels that are corrugated like cardboard. It can be weak if it is thin, flat or planar. Things like gauntlets that are curved are ideal in fiberglass.