Best and outstanding custom Android ROMs for the Samsung Galaxy S6, S6 edge
Regardless of what you think about the new Galaxy S6 and S6 edge, there's one aspect that can be hardly argued with - TouchWiz on both is times lighter and more streamlined than its previous renditions.
However, this doesn't mean that a custom ROM is not a viable option for the phone. On the contrary, a custom Android build usually promises even better performance and improved battery life, and let's be honest here, the Galaxy S6 and the S6 edge can totally benefit of a better battery endurance. They've been out for some time now, and naturally, the restless developers have had more than enough time to develop a custom ROM or two for both phones.
Unfortunately, a problem arises. Due to the fact that the newest Samsung top-tier phones come with proprietary Exynos chipsets, developing custom ROMs is troublesome. This doesn't mean that there aren't any custom ROMs for the handsets, but the notable existing ones are merely a handful. Here's hoping this will change as soon as possible.
XtreStoLite Deodexed Mod Edition 1.2
VN ROM
Available for SM-G920F
This ROM comes with a number of new features on top of... yes, you called it right, stock TouchWiz. For example, it comes with a new baseband modem (XXU1AOE3), supports the Edge Contacts feature of the S6 edge, allows you to modify the status bar clock, key backlight duration, remove the keyboard switcher notification, multi-user switch, various new stock launcher settings, network speed in status bar, and many others. It's not as lightweight as some other ROMs, but this does not mean you should disregard it.
AllianceROM
Available for SM-G920F
With a handful of different system-wide interface themes available from the get-go, AllianceROM is all about personalization and customizing the Android experience as per the individual requirements of each user. A pretty impressive list of added features can be found here, folks - it is even claimed that some of the tweaks and mods in AllianceROM are exclusive to it and can't be emulated elsewhere. We won't mention them all for the sake of brevity, but the most important ones deserve a mention - AllianceROM for the Galaxy S6 is a pre-rooted, zipaligned, de-odexed distribution with the latest BusyBox, init.d, and Sqlite 3 scripts pre-installed; all stock features of TouchWiz, as well as various build.prop tweaks are here; there's also an Aroma installer that will allow you to easily choose which features of the ROM you want to install and which ones not.
WanamLite
Available for SM-G920F
WanamLite comes with a solid feature list that makes it an appealing option for those who are looking for a mostly "stock", yet improved user experience. First of all, it's a debloated ROM which comes with a stock kernel that has been tweaked a bit; root access and BusyBox support are also two important custom-ROM features you get right out of the box. If you are a fan of added functionalities, the baked-in call recording, tweaked camera app, and other interface enhancements should also float your boat.
CarHD ROM v.1
Available for SM-G925F
While it might now suite everybody, CarHD ROM for the S6 edge is a notable representative of the scarce ROM population for the edgy handset. This custom firmware characterizes with inverted, semi-transparent interface that is an either love it or hate it affair. This ROM is based on one of the latest official firmwares (XXU1AODG) and comes with the usual paraphernalia of a custom ROM - pre-rooted, zip-aligned, with the latest SuperSU and BusyBox script being pre-installed. There don't seem to be loads of non-stock features, but it's still an option for those S6 edge users that are not fans of its stock firmware.
VN ROM
Available for SM-G925F
That's right, one of the few ROMs for the regular Galaxy S6 is also available for the S6 edge as well. VN ROM comes with a new baseband modem (XXU1AOE3), supports the Edge Contacts feature of the S6 edge, allows you to modify the status bar clock, key backlight duration, remove the keyboard switcher notification, multi-user switch, various new stock launcher settings, network speed in status bar, and many others. It's not as lightweight as some other ROMs, but this does not mean you should disregard it.
Things that are NOT allowed: