Having watched the NFL video review system in action for almost seven years while I've lived in North America (OMG, is it seriously that long?), it's been blatantly obvious to me for some time that this is the better system. It removes the second guessing and self doubt from the onfield officials, allowing them to get on doing the job they're actually pretty good at, while also removing the pressure and scrutiny from the video official, who is no longer left carrying the can for sorting out all the borderline situations. Now the ref makes his call and that becomes the default position. Only if the call is clearly wrong upon review can it be overturned. Otherwise, if it's disputable or borderline then the existing decision stands. It's a simple standard and it works.
Glad to see Captain's Challenge move forward to a more extensive trial. I think this is one change that really justifies a large scale trial before it is introduced to the elite competition. It'll be interesting to see how it is used in different game situations and what tactics develop around it as teams adjust to having it available. It'll also allow the game to fine-tune the logistics and which situations should be challengable and which not without the intense spotlight and emotion of the mainstream media.
Leigh