They do weight a little, about 25 or 30 pounds maybe... and a carbon fibre hood would weigh about 8 or 10 pounds. So you do save between 15 or 20 pounds, but it all depends if you want to spend $600 on a custom OEM style CF hood.
One thing I've seen done is hacking out and removing the brace from underneath the sheet metal. Not sure what the best method would be for reinforcing it, but it can be done. Once you cut away the brace, it's held onto the sheet metal by an adhesive and can be pulled off.
And the thing I've discovered with LG is it's hard to match, especially if the original is a few years old. I walked into a paint shop and they not only wanted the color code, but the region where it was painted. Basically, a LG paint job from the factory in Wayne Michigan is going to have a different mixture than a LG paint job in Hermosillo Mexico. Silly I know.