[Galaxy Note5 Q&A, Help & Troubleshooting] far_star:
Quick read: I went from the G4 to the Note 5 and am staying with the Note 5 no question. More detail below.

I made this switch. Before the G4 I had the Note 3 which had a extended battery and a 128GB microSD card in it. When rumors flew that the Note 5 had a sealed battery and no expansion I got the G4. The G4 has serious headphone out audio quality and volume issues so bought the Note5. I have the Note 5 since the 21st and here are my observations.

Screen: The G4 has a great LCD screen. I don't like the on screen buttons but got used to them. When I got the Note 5 I remembered how much I liked the amoled style display. Saturated colors, deep blacks. Read displaymate's review of the Note 5 screen. It's insane how good this screen is.

Speed: I never had any issues withe the G4. That being said the Note 5 is snappier. There are a ton of benchmarks of the Snapdragon 808 and the Exynos chip in the Note 5 (same SoC as the Galaxy S6). With this and the extra ram you will be getting a speed boost. On the Note 5.

Camera: There are a ton of G4 vs S6 comparisons out there. Most place the G4 as the slight winner with more accurate colors in low light. In good light both are close enough to not let good-light performance be a deciding factor. The G4 has an 8MP front shooter instead of 5MP on the Note 5. The Note 5 DOES have a faster responding camera and that makes a big difference to me in my camera experience. Both do manual mode and RAW capture. The G4 can do a 30 sec exposure vs 10 sec on the Note 5 which is a shame. In the end, look at the extensive comparisons out there.

Audio: On headphones the Note 5 kills it. The G4 isn't even close and this is what makes me the most happy about the switch. BT, which I don't use, seems to favor the Note 5 as well. Phone speakers are weak on both, but I don't know who in their right mind would listen to anything important on a smartphone speaker.

Battery life: The Note 5 is great and I have made peace with not being able to replace or expand it. The fast charging and 2 wireless charging standards being supported is really useful. If you haven't tried wireless charging then do so. All of my previous phones that I've kept for more than 1.5 years experienced a micro USB connector failure. Wireless charging removes that concern. The G4 does not support this out of the box and that is too bad. That curved back isn't going to make wireless charging any easier anyway. Look again at displaymate's review of the Note 5 screen. It is crazy efficient.

User experience. No real issues with the G4. Their customizations were fine by me. Touchwiz doesn't bother me either and if it does, that is what custom launchers are for. I do love the fingerprint reader on the Note 5. It is so seamless unlocking the phone with it. There are options for expanding the storage on the Note 5 either through the small USB OTG flash drives out there to wireless expansion (look up HooToo, their devices are well loved and I just got one)

Rooting and ROMS: The G4 is probably a safer bet here. There is already root for it, though no custom ROMS that I know of this early. Samsung is an unknown quantity here. There have been some mumbling that Samsung has software that will brick your Phone (especially on Verizon and ATT) if you try to root it, but until a method is found and someone tries it, it is too early to say. Samsung really wants their phones adopted by the Enterprise, hence the knox 2.0 and such. They are probably trying harder to make it harder for those like us to root.

If you have followup questions let me know