Not quite that easy. Verbatim/Mitsubishi has on-site personnel (according to a 2004 interview, when outsourcing realy got started), and they provide much of what goes into the media. There is a real close oversight and participation going on. CMC is just real estate and extra hands, for the most part. TDK has a similar situation, though I think they let CMC weigh in a bit more.
CMC alone, with their own materials and everything, don't really do a great job. They may separate the bad from the not-so-bad for various brands, but a lot of that does not really last. One month BRAND X is poo, while BRAND Z is decent (on some burners only). But next month, BRAND X and BRAND Z are both poo. A few months later, both brands are decent. It's unreliable.
I've seen some excellent CMC results, but then I saw equal numbers of bad CMC results. The good ones all came off NEC burners.
The only thing you'll get from this thread is wildly varied reports.