I have the same tank, and a bobber to indicate full. I only use the tank for grey water. There are 5 of us and I can easily do 4 or 5 days on the black tank, but not the grey. The bad parts: 1. The bobber doesnt work. I have to open that fitting to vent the tank as it fills. 2. My drain on the trailer is low, so depending on the ground/terrain at the site it is possible for the tank to be too tall to fit under the pipe. 3. I tried towing it with the truck once when the dump was a mile over the hill from my site. That was a pain in the neck. I tied a short rope to the handle, making a loop, so the handle was longer - more comfortable to pull while walking. 4. I wish the drain valve was at the back, versus the side. It can be difficult to get all of the water out of the side. If it was on the rear it could be rotated up on the end to get it all out. Now for the good: 1. My truck and trailer are long - 53 feet combined. Some of the camp sites are difficult to get into, so once there I prefer not to move. 2. Invariably, I see the grey tank is full after dinner so my motivation to go dump is pretty low. (The indicators in the trailer panel are so accurate!) 3. I like the flexibility the tank gives me for when to dump. 4. My boys are old enough/big enough now that they pull the tank to the dump. So....plusses and minuses but I will keep the big tank. It travels in the back of the truck. There are mods on here about adding larger pneumatic tires to make it roll easier but the boys are pulling it so.......
