I have received quite a few questions regarding my post on this earlier this year. The original post is located here:
http://owsug.ca/blogs/brad/archive/2008/07/15/Hot-shot-OpsMgr-maintenance-_2D00_-No-alerts.aspx
Let me start by saying that I did know about the warnings in advance against doing this.
My colleagues and I have tested this several times in our lab with no issues. To be clear, this is the OpsMgr SP1 installation. Also, we not only tested this in our lab environment prior to performing maintenance but in the customer's QA environment as well. In addition, a snapshot was taken of the RMS beforehand.
The main reason for my post here was to confirm that precautions were taken and putting the RMS in maintenance mode was not done recklessly.
My opinion is that this definitely works but conditions in the installation environment will ultimately dictate whether there are issues and so the procedure should be tested in each environment prior to being performed in production.