I mainly use hang-ons because they provide more cover in the stands and you don't have to limb everything out like a ladder stand.
I'm very confused on this one.
Don't you have to have a fairly clear shot to climb up the trunk of a tree if you use a hang on?
I can and often do leave bottom limbs on pine trees (etc)using a ladder. I can even useon very twisted trees that would be too tough to climb.