Okay, here are my thoughts...
IP67: The Note has more 'hardware' packed in it compared to other phones. It's not the just the pen... there's sensors and other things to consider that work with the pen. There's the electromagnetic field it emits to detect pen proximity. The sensor within the silo to detect the pen being taken out. Of course Samsung could have gone around it by making a cover that goes over the pen slot and protecting it.
USB 3.0: going back to USB 2 is not a backward step in my view. More of a lateral step since it never fully utilized USB3.0 in the first place. USB 3.0 on the Note 3 was half baked and never offered anything really substantial. Great transfer speeds only if you used it for internal storage. If using it with the SD card in the phone, it reverts to classic USB 2 speeds. So what real benefit was there? And charging only made a difference when using it in a USB 3.0 port which allows for more amperage compared to USB 2. Using mains to charge, again, negates the benefit of USB 3.0. So, in reality, it was literally a wasted feature. USB 3.0 implementation could have been so much better, but Samsung screwed it up on this one.
Also many are relying on cloud syncs and wireless convenience. Rarely want to be tied down to wires despite the fact it's more secure, reliable and faster. I know many here are more tech savvy, but the masses out there are not.
RAM: Android is still a 32-bit OS coupled with a 32-bit processor. So 4GB will not be recognized in this 32-bit environment. The added GB of RAM will be wasted and offer nothing in this scenario. The 3 GB is the best it can handle at the moment. Until the 64-bit CPUs and 64-bit OS start coming into the market, we are stuck with the limitations of what we have now.
Oh well, I'll probably test drive a Windows Phone for my next upgrade. And maybe swing back to Android when L shows up on devices. By that time, maybe we'll see better utilization of USB3.0 and full SDXC card support.