Some early preliminary benchmarks of the A9 chip in the new iPhone 6s and iPhone 6s plus, shows that it beats all high end phones on the market by far.
A9 delivers single core performance that makes Apple's entry level iPhone 6s over 90 percent faster than Samsung's fastest Exynos 7 chip used in its premium-priced, limited availability Galaxy S6 Edge
It doesn't matter if the very expensive high end android phones has 8-Core processors or whatever, the iPhone 6s beats them anyways. It clearly shows how well-designed the A9 processor is. And also how Apple optimizes the hardware for the software.
If you should buy a phone today, there is no other option than the iPhone 6s and the iPhone 6s plus. Heck, I would even prefer keeping my very fast and powerful one year old iPhone 6 than any of the so called high end android phones!