I have it. I rarely use it unless I am going to show the patient a digital DX. It's one of the least expensive modules to add and I think my reseller have it to clients for free and covers it in the renewal of a dongle contract? What are you hoping it does? If it sells more restorations to patient's that are not certain what they want it may be useful in that regard.
We have it on one workstation. It's fun to use when designing, even though your crowns will not look like what you design. Great for presentation, helps sell a case. Evidently you need it if you are going to get the smile designer module. We got it free a couple of years ago as an Exocad offering.