i recently did up my old Raleigh specifiably to pull a trailer a look alike bob.
i packed the bag of the trailer with dust sheets ( i'm a painter)
and just rode up and down the street, to be honest i just didn't like the feel of it at all .
felt like somebody was holding me back ,but my thorn with loaded rear panniers is fantastic i keep having to look behind to see if the panniers are still attached, the bike is that well built , loaded panniers don't faze it at all.
and before someone asked well why the hell did you go to all the expensive of doing up an old bike and buying a new trailer,well you don't know until you try these things.
verdict panniers over a trailer.