If you follow the 'TI vs other swimming methods' thread, you can see that I have linked to an Italian site that has the entire 1500m race available, with lots of underwater footage showing Sun's interesting kick (combination of two, four and six beat, as far as I can see). He has a beautifully even and regular arm stroke with hardly any splash, which contrasts with Cochrane's, which is also very good but with a lot more splash, especially on his non-breathing side.
Cochrane mostly has a six-beat kick, I think, although there aren't as many opportunities to watch his kick in this race.
I think if Sun really set his mind to it he could knock quite a few more seconds off his new record. Probably he would need to swim just a tiny bit faster for each 50, and then he wouldn't need to sprint quite so hard over the last hundred. As he said after the race, he was concentrating more on winning than on setting the record. He had plenty left in the tank by the last hundred.
I wonder if he or his coach have seen the footage of Shinji?