I'm currently using a Burley Nomad for groceries and other errands. Right now I'm trying to decide if I should convert the grocery wagon to an Xtracycle or get a Flatbed. I need something to transport lumber with.

If you're pulling a heavy load, disc brakes are really nice. If I load up the Nomad with heavy stuff, I usually pull it w/ my cross bike that has Avid discs. I took the train up to Portland one time and rode into Tigard from Union Station; going over Terwilliger and down the back side with the trailer was nice with discs, no fade and consistent power. A godsend in rainy weather too.