Smoken Up went 1.48.5. Tinted Cloud not one of the best credentialed sires and his mares side isn't strong. Mr Feelgood ex American was in that race is well beaten 20m. So based on that, 6 - 8 years ago our breed was around the mark with the US.
I don't think we've ever seen a massive leap in progression in the breed at any time in history, always seems to be gradual. The stars don't just fall off a cliff when the new kids come along. So I think its fair enough to say we haven't ever been too far behind the US. Young Quinn once beat Rambling Willie who won 3x US Horse of the Years.
But given what breeders are doing we should be seeing a gradual progression in our Australian breed so it makes sense to see track records.
Meltons records - the 2760 mobile was the Hunter Cup distance for the first time so was a bit of a given.
In the past 14 months how many races have been run over the Melton 1720 and Melton 2240. Could be more races over those distances in the past 14 months than at some distances at Flemington in the past 50 months so thats not exactly a like for like comparison.
As you mentioned one reason could be pacing is still reaching its peak. This could be so given galloping is natural, pacing not so much.
For me, another big reason is the way races are being run. The bigger tracks have seen race run quicker earlier in the race, and this type of driving has also crept in at other tracks. Seeing less and less sit up and sprint races, and more races being run at a genuine pace. This has always been the case in the gallops. Our last 400 has traditionally been the quickest part of the race. Gallops last 400m isn't necessarily the quickest part and can sometimes be the slowest part of the race. This style of racing is slowly creeping in to harness racing which leads to the overall time being quicker.