Notes from my thread on an aborted TransAm ride (search on "Map 12" if interested).
Gear: We both began the trip with front and rear panniers, handlebar bags and stuff on the rear rack tops. At one point Jeff had an equipment failure with a front Thule pannier so we returned to Richmond for repairs/replacements. I wound up borrowing a friend's B.O.B trailer that I've been wanting to try and Jeff used one pair of my panniers to replace his damaged ones so we set out again with considerably different setups. I found the trailer to be more stable but my all-up weight was greater. Kind of a wash but the trailer does have the added hassle factor (additional length, different sized wheel, etc.) and the single large bag in the trailer is more difficult to compartmentalize than individual panniers. And if you open it in a heavy rain you'll want everything in it bagged to stay dry. Another issue was weight distribution in the bag. The items you want on the top, food bag anytime and tent at the end of the day, were the heaviest and seemed to affect the handling a bit. Nothing serious, but any packing change meant trading one hassle for a different hassle.
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Additional thoughts:
Stand-up pedaling on climbs is easier with the trailer than with the four panniers; you can rock the bike from side to side more easily.
I had a tiny bit of sway with the trailer, less than I had with the four bag configuration on my RB-T. The sway on fast descents was disconcerting and I've experienced it with different bikes, so if touring in hilly country would prefer the B.O.B.
I would definitely recommend a B.O.B. over a two-wheel trailer. The single wheeled trailer's single track will be much narrower than a two wheeled trailer.
Also, and someone else might be able to comment on experience with this, the lack of eyelets does not necessarily preclude the use of racks. P-clamps (AKA Adel clamps) might serve to mount the rack on the fork blades and seat stays. I know they can be used with fenders (which your friend might also want for touring) but have not tried them for racks supporting loads.
