Re Platinum upgrades: I was upgraded from a tropical pool villa to a seaview. But was in July 2015 and occupancy was quite low (around 50% I would say).
During our last visit (early May) I booked a seaview and there was no upgrade available to a beach front villa as there are only a few of them and the resort was fully booked.
As already pointed out: enhanced for a seaview means that you will get a villa with the better location and there was a difference compared to the seaview villa we had last year (villa's located to the right of the Z bar have the best views).
Platinum treatment is very good at this resort. Full BF, late check out (but will depend on occupancy obviously) and Platinum Happy Hour at Z bar. Happy Hour changed to 4-6 PM IIRC. Perhaps they had too many wasted Plats at dinner time
Overall I can highly recommend this property. They have a very good hard product, the villa's are very nice to spend a few relaxing days. Service is not as polished as you would get at Aman, but this is also reflected in the rate (Aman about 3 times more expensive). Food is good but not an absolute highlight. Make sure to try the tapa's at Z bar (as already suggested in this thread), perfect for a light dinner!