We thought it somewhat necessary, however, for our more civilized guests to have access to these facilities, namely the So Cal in laws; and in the middle of a 15 degree snow storm it does feel good to take a rare indoor crap.
If it was entirely up to me, an exceedingly rare circumstance, I would retain the private potty option, but eliminate the tub and sink. In the cold months it simply feels best to wash off with a bucket on the floor in front of the blazing wood stove, which also at no extra cost can produce gallons of hot water. The rest of the year the outdoor solar shower provides limitless baths.
So on the top picture is the 5' tub with a hand-me-down Paloma on demand water heater. This unit is very old, but generates scalding hot water for as long as you keep the faucet open. We manually mix with cold to achieve the right temps.
To the right is the sawdust potty, a system lifted straight out the excellent Humanure book. More about that here.
The 50 gallon tank to the left is our water supply, filled from the well when needed. If there is anything we might get really worked up about in casual discussions with friends and strangers, it usually centers around peoples wasteful attitude to water usage. For us, these 50 gallons seldom lasts less than 2 weeks for all uses by a family of three.