I've never made anything with the bearing roller type setup but I do know a bunch about drawer slides.
Plus for bearing rollers is that they are probably less susceptible to dirt and dust. However, I would only consider this an issue if it is an open vehicle.
Plus for ball bearing drawer slides is that they are full extension giving you full access to all the drawer contents.
Plus for ball bearing drawer slides is that they can also be purchased in LILO (lock in/lock out) versions.
Any 250 pound capacity full extension drawer slide could be rated much higher if it had a stop to only open 2/3 or 3/4 of the way like the bearing setups.
2008 Sandstorm FJ Cruiser, Level 8 Guardians, Cooper STMaxx LT285/75/16E, Radflo suspension, Total Chaos UCAs, BudBuilts, Exp One w/Superwinch 9000s, BajaRack, Dual batteries, MetalTech upper and lower links and more
I'm the Woodsman, the four-wheelin', tree-farmin', custom-furniture-makin' descendant of Olaf "The Woodcutter" Ingjaldsson.