As somebody earlier said, the ability to stop is the key. The RSV, two up, will pull 325 lb camper (full of gear, so about 425-450 lbs) just fine. I keep the tongue weight less than 30 lbs...while you can feel the weight pulling away from a stop, and you definitely know it's there slowing down, at most times it's hard to tell the trailer is back there.
One pix is our 99 with the Bunkhouse, and the other picture is our friends 01 with their Hannigan sidecar and their bunkhouse...they typically have 3 people riding (two adults and their 16 year old daughter). Gas mileage isn't that good, but the RSV has no problem with the weight.
Curt