I had a max 6 wheeler a few years back. My property is similar to yours with steep hills but I have a good size creek bordering my property. Ended up selling it because it never ended up fitting my needs.
the bad
1. It was under powered because it would run out of power on steep hills; I did have the smallest motor available so maybe a bigger motor would have helped.
2. The ride is rough at any speed. With no suspension except for the tires it gets old fast; I did play with air pressure but never changed the ride dramatically. I hear the new argos have a new tire/rim combo that improves the ride.
3. It doesn't do good in moving water. After you started floating you were at the mercy of the current.
4. Top speed bothered me because it just takes you that much longer to get somewhere.
the good
1. It was very stable in any situation I encountered.
2. On the level it would roll over saplings like no ones business which was nice because you could make your own path.
It was fun at first but it never did anything great so I ended up going back to a quad.
