I agree with Testa.
Rain Gauge for me. Has demonstrated excellent speed and acceleration and shown on more than one occassion that he is up to G1 standard at WFA. Has also proven he goes ok at the distance with a good run in last years cup.

He's a a 5YO now and should be hitting his career peak this prep. The experience of last year and all the factors mentioned above give him pretty good credentials to take out the big race.