I haven't read the whole thread yet ...
Monopods do have their uses, though a tripos with thei legs closed up can provide just as much benefit, though weight may be an issue.
Monos are great for reducing vertical movement associated with a heavy lens leaving you with horizontal (and front and back) movement to deal with. This can be particulary good for panning or fast shutter speeds needed for macro work.
If you are into landscape photography leave your mono at home as it is unlikely you will get good results with the shutter speeds required for a high F/# (great DOF).