We also found this is a practical thing to do. It can be a hassle, though, because you need to (and usually forget to) disable it when you are debugging.
Moreover, as a comment to the original question: I have once, some time back, had a browser running (I do not remember whether it was an IE), that was not closed by this procedure. So, in rare cases you may have to open the Task Manager and do you own killing.
in our tests we always distinguish between machines where tests are run and machines where tests are debugged and created.
so we do not have to think about disabling anything when debugging tests.
this helps in lots of problems within the test.
also we wrote an extra routine to close processes. we also use this to close browsers as Browser.Close() is not always working in our case.
We will also kill all the browser processes before we start our tests.
check all the other events TestComplete provides.
some of them will be useful for you.