"One possible explanation is that the Geekbench suite itself isn't yet optimized for the Apple A8 architecture"
Hint: The WHOLE point of a benchmark is to NOT be optimized towards any specific CPU, but rather reflect how things would work-out in real life.
And who the hell told you that the note 3 had used a Qhd screen it`s only a full hd screen.the note 4 will be the firs samsung`s smartphone to use the qhd screen.
iPhone 6 got more ram then 6 plus, even clocked higher? I guess only thing it's got going is bigger screen.