VEX needs to find a way to make the Versaplanetary gearboxes weigh essentially nothing...
I mean, they are so versitile and easy to use that when you have (10) 2 stage gearboxes, (2) 3 stage gearboxes on your robot, all of a sudden it starts to get pretty heavy or nearly over-weight.
In all seriousness, we used almost exclusively all VEXpro parts for mechanism gearboxes, bearings, shaft collars, and drivetrain components (belts, pulleys, wheels, etc...). I can't even think of what else to ask for...all the products offer such high quality and versitility for a robot designer.
*Edit - We actually ended up not using VEXpro belts for the drivetrain. We had to switch from the 9mm VEXpro belts to 15mm wide, 5mm pitch Kevlar corded belts from Mcmaster (
http://www.mcmaster.com/#timing-belts/=wyasp5) because we were skipping and failing them on our practice bot drive system. Forgot about that. We will not be using the 9mm belts or any non-kevlar belts on our drive systems any more. Just doesn't seem worth it to risk failing a belt and an inopertune time of a competition.