"Are you of the opinion that using this technique is “cheating?”

I don't care is it is cheating or not. All that is important is the result. The whole motion picture business is kind of cheating as is art in general. But this technique doesn't produce good results.

If you are going to use real actors voice, movement and emotions you are better off using the very same actors in the normal way to get a better result. The first  Lord of the Rings movie was produced this way and was a failure. Peter Jacson's version with real actors on the other hand was one of the most successful films in history.

Performance capture loose out more than 90% of what that is possible with CG. Art is about distilling -lifting out what that is important so people get the message and not get lost in insignifant details.