I am not yet set on my path. I may create some bags based on an Army pack, or I may build a slightly smaller version of the Buckets Of Doom. I may do both! Either way I go, I need to decide how to attach it to the bike.

Ortlieb's attachments (QL1 and QL2 systems) get rave reviews. They prevent bouncing at the lower attachment point.

Arkel has a kit, which is cheaper and simple to install.

Does anyone have experience with these (or other) options?

Edit: BicycleTouring101 has a great article which goes into detail about the attachment systems of Arkel, Ortlieb and Vaude. According to the review, Ortliebs are extemely easy to mount and remove from racks, but are harder to set up. Arkels take more time to mount and remove, but are very easy to set up.