After using my SGS for 2 year it still can handle most of the task i throw at it.Although it needed some tweaking to run smoothly. Root , custom rom , custom kernel , overclocking , swapper for root , greenify and many more.

One thing i can't tweak is the ageing GPU.That why my
next phone will focus on GPU performance. Most of the app now a dual core can handle already.Only some of the high end game on android take advantage on the quad core.But the burden is still mainly on the GPU.(One of the reason Apple products run smoothly even in dual core).

That being said tech move very fast.Having a future hardware spec may turn in your favor or may not in the future. Right now most developer are to lazy to take advantage of the extra core because of the headache to built and debug.Even the quad core on desktop and laptop haven't really push to the limit yet by developer.

What would be most exciting spec i want is BATTERY!!!