I've often wondered (and I'm sure the answer varies from MSC to MSC and client to client) - how much work does an MSC put into aggregating and reporting our results vs just passing the results raw back to clients for them to make sense of? For example, are clients hiring MSCs to help research customer service attributes (where the client might say "we care about quality of service" and the MSC helps define the questionnaire, gathers results, aggregates them, and presents a 20-page market research report with findings) or to get raw data (where the client might say "we want to know what the wait time at the drive thru is for each and every store - just ask shoppers to time it this way and give us the raw numbers to do with as we please"? Just one of those things I've wondered about...
It really depends on the client requirement. Some will want an exact, others will want a range. Commentary usually goes through as the shopper writes it with few exceptions (spelling or grammar mistakes or anything that would likely get you suspended from shopping - like vulgarities). Hope that helps satisfy your curiosity.
You may have noticed that some of the msc we are assigned ms through are actually large companies that specialize in all areas of consumer research. For these large sometimes multinational companies the mystery shop program is just one piece of the puzzle they put together and they have staff with wider expertise than a small company that does only mystery shopping. I would imagine clients that want to have the results of a mystery shop program be presented as part of a larger more comprehensive package of information and help with making changes to their business would be able to find what they need depending on which mystery shop program they sign on with and how much they are willing to spend.
I temped at a small MSC for a summer, and yes there is a lot of data analyzed and reported to the clients. In addition to the shop reports, there are frequent corporate recurring data reports with trends, statistics etc. that are provided regularly in big presentation binders. It seems some MSC use a standard report form, while many corps engage in specific, timely and detailed regional shopper reports. It was a small company, but it was interesting seeing that side of the industry.