Depends on the practitioner.....
C, O, P are all manual therapies and work on the basis of restoring movement. Each profession has a slightly different viewpoint from which it works and each practitioner within each profession will have their own stance from which they work.
C, O, Ps (should) have a thorough grounding in anatomy and neurology (superior to GP's) - C and O will also have taken physiology to the same level as a medical students.
C, O and P all will use relatively similar techniques, but there tends to be more manipulative techs (cracking) with C, more soft tissue (massage type and ultra sound, electricery muscle stimulation) with P and more articulation (moving a joint through its ranges) with O - but all of them may use any treatment modality at any time (!) They can also use additional techniques such as medical acupuncture if they have taken the appropriate courses.
Acupuncture - there is Chinese (which works on the basis of energy lines in the body) and western, or medical, which works on the idea of stimulating the neurological elements of control of the muscles (as far as I understand, don't use this myself so am open to correction)
As for Pros and Cons - many people get tremendous help and pain relief from each type of therapy, there are also many people who lambast the therapies and say they are a load of quackery.
From my perspective as an osteopath I try to look at why the patient is presenting in the situation they are and what can be done to enable the natural compensation and adaptation of the body to deal with whatever issue is going on.
HTH