I'll also add on my complaint about tooltips.
In the tag designer, if you're editing a tag or UDT instance that has an expression in it, if the expression is longer than the display area a tooltip will pop up showing the entire expression. This isn't a bad idea, but it completely covers the expression link button.
If a user wants to edit this expression they have to expand the tag editor to show the entire expression which will remove the tooltip. The downside is that if you have a long expression the tag editing screen may be expanded to the width of an entire monitor and the tooltip still covers the expression link icon.
As @ jacque_trahan said above, this isn't a bad feature, I just wish it would pop up somewhere else other than right over where the mouse is because the tooltip gets in the way. Maybe offset it to the top or bottom of the cursor