I'm surprised the Traveo dry toilet isn't used in the high end units. Allows for more space and its removable to use in a cabin or what ever. Its about $1 a flush for the cartridge but no black tank, hoses etc... I haven't regretted it since all you have to do is pull out the cartridge and toss it in any trash can when full. So far one cartridge has lasted us the entire 3 week trip we are on. How much is it worth to you no to deal with dumping the black tank? We just have a water hose for the gray tank.