belt drive VS chain drive

You can make anything work well if you put enough work into it. If your team has the means, I would suggest trying everything you can. See for yourself what works well for your team and what doesn't. Try and make a modular design that will allow you to swap out parts to see what will work better for you. For the most part, there really isn't a universal "better" design choice for teams.* You can be successful with anything if you try hard enough.

*While there is no "end all be all" best solution, there are some that are generally more effective than others given the circumstances of FRC and the style of competition. Of course, those are all case dependent.