Hi. I'm new to the android zone and just converted from an iphone to an Singaporean note 4,n910g, so looking at this, I was able to feel the same feelings as you did. I have also heard about the Dr ketan ROM . however, as i have said, I'm new to android and would not like to flash a bootloader and modem which can essentially kill my phone if I screw up. I am now running sokp ROM which was meant for trltexx, the n910f variant. Installation is fairly simple compared to others I have read. Just wipe data, systems, cache and dalvik and flash the provided ROM, wipe data and dalvik, and gapps 5.1 and wipe data and dalvik , which is provided by highonandroid(for gapps 5.1). It is super smooth compared to the touchwiz stock ROM my phone came with--it is a aosp ROM if I did not mentioned--, and I wasn't able to find any big bugs in this ROM except for the buggy sonic launcher which is fixed by installing a custom launcher from the playstore. One note is that the pop-up you normally get when detaching the stylus is gone. But it is a worthy trade off, for me that is.
The stylus still works as it supposed to be, so its fine. Hope you'll try it out. But give the time like 10 months give or takr , you have probably tried and found a nice ROM for your phone. Have fun.
PS its my first time posting a reply on and technology or android forum so forgive me if I'm abit wordy. Really hope this helps anyone searching for a ROM for note 4.
Links: sokp ROM : google and go to XDA site
Gapps : use highonandroid or manually search for a newer and suitable for your use gapps 5.1 on XDA or just google.
(Can't post links yet. Sorry)