I have been using the internet since before the www. In the last few years I pay attention to every speed bump and evaluate it seriously. I check the url of every financial site I log into. I disable automatic security blocks as a last resort. There's just too much consequence for failure.

We recently rolled over an SSL cert that is used for RemoteApps. Most of my users rely on these RemoteApps. They all got the 'yellow warning box' that the SSL cert was different, and we got swamped with tickets.

Atleast in a corporate environment, they help