There is one minor issue with the 933 test number though. For anyone who their E911 setup on a different call display than what they have set to show for the phone they are using (either account wide call display or a per-user call display), the 933 will give results based on their own call display. Only actual calls to 911 will force the call display to be your Emergency call display number.
This only applies to users with multiple phone numbers, and dialing out without using their main number/E911 registered number.
If you still wish to test, you can just temporarily set your call display to your E911 setup number, by removing personalized call display on your user, and setting your company main number to the same number as E911 is setup on.