I took part as a mentor. Overall there was only one main difference which I saw in the mentees versus in the wild so to speak. Attentiveness.
In chat, if we asked for an update or an inclusion, the mentees would very often make an attempt at doing that for the question to be well received.
In SO main, if you ask an OP to make an update or an inclusion, the odds are pretty low that it will happen.
To me, this was the main distinction. If nothing else, this process allowed for new users to experience how attentive they need to be in order to produce a well received question without actually having a question pulverized on the main site.
It was also interesting to see the reasoning behind some very, very, very low quality questions which would normally not see the OP return. A For the most part, a request for terminology seemed to be behind them for the most partthese posts. I think many times when a user asks how to foo the bar, we assume we need to make it for them, when often this assumes some malice. New users don't tend to ask for implementations so much as terminology or a broad view of how to accomplish the task, but it certainly reads as "build me the next facebook app" to most veterans here.
I am not sure what reconciliation process is available there, but it would be nice to sort it out so we don't constantly feel like people are asking us to do free work in the form of building or researching; and so new users don't constantly taken aback for asking about identifying process or technology.
One aspect of the workflow that sparked my interest was the ability for this to be turned into a queue. There is a preview, a chat room the user is in, and an entry point. I would imagine that there should be a way to make a queue for these mentee requests as the basics of the tooling are already built. This could greatly help build community and increase question quality.
I think the staff running this experiment did an excellent job. Jeremy did very well implementing the feature sets, Kristina was very available for communications and kept everyone in the loop, and Joe provided insights and feedback into the overall process.