Been there. The mindset in an MRO is that they are a business and will make money any way they can-- can get away with. In house work takes a bit longer sometimes because quality and reliability are a little more important. asian and south/central american MRO's put out junk. There is less oversight overseas for the obvious reasons.
In house work is performed by 100% liscenced technitions, MRO's require a small percentage to be liscenced 80% of the work is done by great walmart candidates who do it because it is just another job, not a profession, then inspected by a liscenced Technition.