I am against the referral system, wholesale.
It disrupts the flow of the game, and also reduces the onus on the on-field umpire in attempting to make the best possible judgement. Watching the last days play of the NZ vs WI test was at times extremely tedious with endless replay after replay, something that is only likely to be worse with the addition of snicko and hotspot and all the other gadgets. Commentators forever repeating the obvious with every replay, or speculating at the possibilities with extended replays, just made the game even worse as a spectacle for the audience. I imagine the effects on the players in terms of focus and tempo would not have helped either. Leave it up to neutral authorities on the field, suck it up if you get a tough one (it is part of the game, and usually evens out), and get on with the damn game. Worse, the sharing of judgement between player and umpire (which is what the referral system effectively implies) means that there is less of an onus on umpires to give the best possible decision. In other words it is easier for an umpire to give a non-committal decision with the thought that if the player thinks otherwise they can always refer it to someone else to adjudicate. It devolves responsibility on the field, and is conducive to sloppy umpiring.
The silly experiment should be scrapped.
Finally, McCullum's exhibition yesterday was a disgrace. Sure he copped a poor decision from Rudi, but that is no excuse for his petulant carry on after his dismissal and again after the game where he seemed to, again, exchange some words with Rudi. Fair enough you dont want to pull a Sanga and show some class (after the Hobart test last year), but at least shake hands and walk away without mouthing off. After all, its not like McCullum has not in the past appealed for decisions which were not out, or benefited from decisions that were given in his favour. Its just hypocritical and reeks of double standards. I hope he is well fined, or even suspended, for his behaviour.