Fiberglass is stronger, same with carbon fiber. Reason you don't see it in automobile bumpers and more commerical use ect is cost reasons. Theres a reason aircraft panels and misc parts are made of FG and CF (im an aircraft mechanic I know) and not plastic, lighter and stronger. Also a reason why larger sport boats are made of the same. Plasitc is a awesome material, but is limited.

There were A LOT of new guys asking questions on up grading there Spartans and Traxxas deleted all those threads. Any thread or post that linked to a lipo or esc from hobbyking was also deleted and the user banned. There was also issues with the Spartan hulls starting to seperate one video I seen over at OSE a brand new Spartan hull completly seperated on the first run. The said part was a lot of the the post I read before they got removed weren't bashing Traxxas just trying to make there boat better.