Apple's newest flagship was benchmarked yesterday, and the results were quite good. The program used for testing is called Geekbench.
The iPhone 6s managed to obtain a 2,292 single-core score, and 4,293 for the multi-core run.
If you want to comapare it to the other flagship phones right now, take a look at the graph below:
As you can see, iPhone 6s loses with Android phones in multi-core category, but wins while comparing single cores. This all makes sense if you think about it, since Apple is known for optimizing their products. While the specs may not be the best, Apple makes the best use out of them.