I think it depends on where the axles are located on a trailer. The farther back they are, the better it'll tow, but the more tongue weight it'll have too..
My little 22' trailer has it's axles located more towards the rear than the front. The fresh water tank is centered over the front axle and extends to the front.
When full, this gives me the most stable tow. When empty, I can tell a difference, but it's still a stable tow.
My waste tanks are at the very rear of the trailer. They are normally empty, so a non issue, but I have had to tow with them partially filled and could not tell much of a difference in handling.
So, I think it really depends on the trailers axle placement in the end.. ;)
Mitch