Through the years, we have built a
bolted chassis, a
riveted chassis, a
glued and nailed chassis, and a
welded chassis. All have held up to the stress of 2+ regionals without issues.
You can build a chassis that is strong and light in countless ways if you put enough design work into it. The thing you need to ask yourself is how you can best utilize
your resources to build a strong/light chassis as quickly as possible. The faster you can finish fabricating it during the build season, the better.
I would also encourage you to take a look at the big picture when you are designing your chassis. Robot functions change drastically from year to year and greatly influence the design of the drivetrain (hence why we have gone through so many different forms). Remember that you are designing and building a complete robot; the chassis and manipulators are not always independent systems.