Since Steve in Peoria mentioned that he's holding his breath for a ride report on the epic (trademark Rapha) dorkaleur/World's Largest Handlebar Bag combination, I figured I'd better bang out a quick writeup before he turns blue and topples off his recumbent.
In short, the ride is surprisingly anti-climactic. In my pre-dorkaleur days, I tried the Xootr Crossrack and Arkel "big orange sack" in both a front-mounted and rear-mounted configuration without any rack support. On the rear, there was a definite "very heavy tail wagging a very small dog" effect. On the front, cornering got downright spooky. The big bag seemed to want to pull the front end over into corners, very much like overloaded and unbalanced front panniers. Of course, with no front rack under it, i had to mount the rack higher to avoid front wheel interference, and the higher center of gravity was not a good thing.
In dorkaleur configuration, the load rides a little lower and gets some support from the front rack. The result is a bike that just corners like a bike -- nothing terribly out of the ordinary. The steering may be a little heavier, but on a small-wheeled bike, the front end feels a bit light to begin with, so it all balances out. With that much bag sitting right out there in plain sight, I fully expected at least a little placebo effect, but after a week of commutes, nothing.
With all that said, I've actually de-dorkaleured the bike because, frankly, it's just SO much overkill. How much bag does one need for a 4-mile (round trip) commute, anyway? Plus, I stumbled into a great deal on a Jandd Duffel Rack Pack that's more appropriate for my commuting load. Of course, being unable to leave well enough alone, I've done some custom tweaks on that as well, but that's grist for another post.