farmer's daughter wrote:
I took my new trailer on the road, and it felt "funny" like a back-and-forth motion; I didn't like how it was handling. When I got to the campground, my daughter pushed the fresh water tank sensor and it was full! Apparently the dealership had filled it to check that everything worked, and didn't empty the tank. I emptied it, and on the way home towing was a breeze. I don't want to haul an extra 400 pounds of sloshing water.
If the tank is full, the water isn't sloshing. :B
If I had to guess, the biggest difference you saw was from the changed weight balance of the trailer, especially if the water tank is behind the axle (and so causing the tongue weight to be lowered).