Why are you bring up a 2+ year old article? Atom is a joke compared to the latest Arm processors especially from Apple. They were competitive for a few months in 2013 when their new chip came out and that's about it.. Hasn't improve much since then.
And the version of the benchmark they test has been discredited as it unfairly biased Intel
http://www.dvhardware.net/article58877.html
How can you dismiss geekbench and then blindly believe a benchmark a 2+ year old article which later on was determined was invalid?
Btw.. There are a large amount of benchmarks where the 6s has shown to be very close to core m is cpu performance.
Here is a thread where users have released run quite a few:
http://forums.anandtech.com/showthread.php?t=2449308
Gpu performance is another story. The apple a9 in the 6s is a lot faster than the MacBook.