Would it pay to have a list of more advanced questions when I go on in January?
From a practical standpoint, I think you'll often get better, more complete answers here on this forum. Here's why...
The webinars typically last about 25-35 minutes. During the webinar and for a few minutes afterward, there is a team of Marriott personnel (other than the presenter, who talks as slides appear on your screen) ready to answer any questions you have via exchanges of text. You type in the question. Someone types a response back to you. There is limited time, so answers might not be as complete as you might get here. Also, your typed questions and the responses, if you so choose, can be seen by all webinar participants.
Also, on the webinar you get a response to your question from only one person. Thus, the Marriott people on the webinar should be able to answer technical questions accurately. But if your questions are along the lines of "What is your opinion of the best way to....", I think TUGgers will be a much better resource.
With all of that said, I found the webinars had accurate info, even if not complete. It's tough to be thorough in such a short time. As an example, my webinar on using Marriott Rewards points was held about a week after the announcement of the changes that will become effective January 15, 2009. The presenter had not planned to mention anything about the changes or even that there would be changes. It was only after I posed a question (for all participants to see) regarding the changes that the presenter came back - after the end of the presentation - and made a brief comment about the changes.
