Number of cores over 2 is pretty much irrelevant in real-world performance on a phone (even 2 is a waste much of the time). It is even a waste on many bigger systems too, depending on the user and apps. And the Evo LTE is no certainly no slouch with the S4 chip. Most people aren't playing hugely complex FPS on a phone or trying to transcode video or trying to fold proteins in a complex scientific simulation.
However, the amount of memory (which is RAM) can make a big difference when it comes to the way an Android device can delay swapping out stuff or resorting to suspend-and-reload. 2GB is a real-world advantage for task switching; especially if your device is going to run a "heavy" launcher/environment on top of Android, like the HTC phones do. Of course, I would guess that 90% or more of Android users have no concept about task switching vs. multitasking vs. suspend-resume, etc. (Don't feel sad, probably 99% of iOS users don't
)
Oops, I am supposed to be in bed...