I tend to get up early, and I like the peaceful walk to the shower house. Once there, because I got up early, I enjoy a long, hot shower with no worry of water conservation or burnt propane.
Besides, our little 19' TT has a tiny little shower. I am not a big guy, but I want to splash around and get all soapy....without tearing the curtain from the hooks or splashing the celing.
Wife used it once to rinse off. Shower house water went cold, she came back all soapy :M AHHHHHHHHH soap UNDER her clothes :E
Having said this... boondocking (which we tend not to do) or if the shower house was disgusting...that is why we have a trailer with a shower. I would use it because I do not want to be soapy, mad guy flip-flopping back to the TT.