Planta, Astroboy & Guru,
Yes, there were many views on whether to change the engine oil at 10k, 20k or 25k even though the are still many bars left on the service indicator. Many has argued that the brand and its vicosity make the difference even though it's fully synthetic!
The same goes for the ATF oil, life time or otherwise. Based on personal and many other owners' experiences of various series, it's best to change engine oil between 10-15k and ATF oil every 50k. These are not big ticket items, so why risk, yes?
Cheers