I currently have 3.
Don't be fooled, while most Unimogs are happy at 88km/h, you can get Ambulance, firetruck, police, or other models with the high speed axles. My RW1 (rescue truck) will do 109km/h (68mph) in 16th gear, it has 16fwd, and 16 reverse gears, so yes, it goes as fast backwards as it does forwards. You can get mogs with up to 24 gears, with a splitter that's 48 gears, super crawler goes as low as 4000:1
Mogs are available with 3 PTO's, Front, Rear, and mid-mount (side PTO in the old models) the Mid mount is a high speed PTO for running high flow hydraulics for things like picker cranes etc. Combined with a front or rear 3pt hitch, full 240bar hydraulics, and nearly any accessory, they are very handy.
They are favored among German and UK farmers, as well as forestry, mining, and nearly any industry that you can think of.
My Rescue truck returns an honest 15mpg highway driving, for a 1988 136hp, 13,000lb vehicle, I think that's pretty good.