I've collected about 3 different hoses over the last 8 months -
-White 25' 1/2" that I normally use...
-another 25' 3/4" for backup, though these are harder to wind up and store
-Blue 25' 3/4" for infrequent waste tank cleanout
on several occasions I've had to connect both whites to reach the water spigot, with one of these being at GrandCanyon RV park when the site spigot handle broke off - I had to extend my reach over to the next site to hook up to water.
it's always nice to have the extras when you need them.
Note: a 5'-10' hose will probably never be long enough for most places
I think it's like your sewer hose length, about the time you think a 10' will serve well, in most parks you will be about 6" short!