Elevation is the key. The higher up your eyes are in terrain that has obstacles the better your view will be, and in turn, you will see more predators. Paths open up before your eyes that you never could have seen just standing there. Cats and coyotes that attempt to sneak their way into a stand using vegetation are many times in plain sight now. The hard charging coyote that is coming at mach 1 to the caller now is seen at 100 yards rather than 30.
Getting a better view by elevating your eyes to 9' is just one reason ladder hunting is successful, the other is fooling the coyote and his 'horizontal plane of focus'. A coyote comes trotting in through bushes scanning his immediate surroundings for that screaming rabbit. His eyes are looking for movement and are concentrating on a horizontal lines perpendicular to the ground probably 1-2 feet off the ground. That's where the last 50 rabbits he's captured were located. Suddenly from 15' ahead of him the rabbit goes silent and he is left walking around looking into bushes and brush for that rabbit. Little does he know that you are sitting motionless 10' to his right but also almost 10' vertical. He is oblivious to you because you've pushed your ladder back into the limbs of a tree and you are making practically no movement. All you now need to do is swing that shotgun down in 1 fluid motion when his head is turned and dust him. This seems almost too easy and really once you get the basics down, it is. I have had coyotes with in 3' of my ladders base with no clue I was on it. I had a bobcat walk UNDER by ladder coming into a stand.
I walk a few hundred yards out to a stand from my truck generally. Carrying it is really not a hassle. I swing it up on my shoulder and the other shoulder carries my shotgun on a sling. I am not large in stature and 42 and carry one all day long- 15+ stands with no problem.
Successful night callers always use elevation to their advantage. A ladder would be a logical tool.
I imagine a ladder will work anywhere there is thick stuff. West as well as back East. I have seen Rich Higgins use it successfully in a cotton field. I have seen him use it successfully in the middle of a flat dirt area with nothing to break up his human form other than his 3d leafy poncho he wears. Coyote walks into opening, looks at ladder and dismisses it as a threat and continues looking for the screaming rabbit.
Its just another tool in your bag of tricks. Some guys don't want more than 1 or 2 tools while others get suckered into every single new tool that comes out. All I know is when someone shoots 70+ coyotes in a season from a ladder, there has to be some advantage he's getting. I need every advantage I can get. I'm not getting younger and my eyes and ears are in a downward spiral.
As I mentioned above the basics to advanced ladder hunting techniques are covered in an article in Trapper and Predator Caller that comes out on shelves next month.