Rugby league over here has been plagued by delays in the past whilst the video referees review something over and over.
It depends on a lot of stuff, can the ref halt the fight to review during a round,who reviews it and makes the final call, do they let the ref see it from a different angle on the screen and decide, lots of stuff to be worked out on it but all in all a good decision.

A lot of old hands would be sweating that's for sure, no more sneaky hits on the refs blindside, or acting like someone ripped your balls off for a hit on the belt.