I have a Carradice Nelson Long Flap with the Bagman support.
Pros: Keeps bag from swinging.
Cons: I dunno. It costs money? No lugs?
Order from one of the UK sites to get a reasonable price. I got mine from Wiggle for like $25.
Originally Posted by
RI_Swamp_Yankee
Another option for a support that mounts to the frame rather than the seat or post is the "Silver Hupe"(sic) from Rivendell.
I've heard about that thing gouging the hell out of frames.