I've heard a lot of "I almost crashed" or "I crashed" stories with trailers. Some friends of mine toured down the Mississippi trading off a trailer that was loaded with a guitar and maybe some other stuff. On a long, fast descent, my buddy hit the brakes pretty hard for whatever reason. At that same moment, the trailer went airborne somehow (my other friend recounted this, as she was riding behind him) and jacknifed before making contact with the road. He very nearly lost it at speed.

My opinion based on this and other stories -- no trailers. Also the temptation to WAY overpack them, since the space is there. I haven't ever toured with a trailer, though, so I suggest you try it carefully and see what happens.