I would have to agree, the question posed, is too simplistic.
There are good and bad points, not just either, or.
Dependant upon whereabouts’ you sit within an organisation will colour your response.
Consider external MES approaches as a hurdle to be overcome (when some bright spark thinks he can save money short-term). A measured response from a clued-up Manager, backed up with some Benchmarking data, normally nips this in the bud.
Plenty of examples of this sort of "market testing", it is usually prudent to be prepared for such eventualities these days.
