My personal experience with Internet Explorer, (IE), is quite limited and I haven't used it for about five years. Now, this doesn't make me smarter, I just got sick of "IE" getting in the way of my work. IE can often be intrusive to deal with and is usually slower than my favorite, Firefox.
Many corporations stick with IE as their default browser because it keeps troubleshooting simple. And, many third party corporate intranets are built to only be supported and controlled by IE.
If you haven't tried the other browsers, I would encourage you do to so. Each browser has it's pros and cons. I find that Firefox allows me to add on functional components that help me with my professional responsibilities and personal enjoyment without sacrificing speed.
What is your favorite?