[Galaxy S III I9305 (4G LTE + 2GB RAM) Android Deve] Oswald Boelcke:
First Observations RR-N-v5.8.3-20170524-i9305-Official-HWC

Despite the described system now only in use for a few minutes, I'd like to share my first observations.

Procedure I used and a few remarks:

Gratefully being still (and going to remain) on TWRP 3.0.2-1, I took a NANDROID backup of my previous system. Rebooted into system afterwards.

As I didn't now if Substratum works with "HWC" I uninstalled all overlays and froze PitchBlack and Substratum as well as Boeffla Control. Unfroze Kernel Adiutor.

Booted into TWRP. Flashed Magisk-Uninstaller-zip.

Wiped dalvik and cache. Flashed "HWC" and @Option58's screen cast fix.

Flashed Magisk v12 (Remark: As you know I wanted to go GApps-free, and I require Magisk for that).

Booted into system.

"Normal" booting time. SIM and mobile network. Checked Magisk Control - Magisk v12 installed but no root.

System reboot - still no root! At that point I knew I won't be able to go GApps-free!

Booted into TWRP. Flashed Magisk-Uninstaller-zip.

Wiped dalvik and cache. Flashed "HWC" and Option58's screen cast fix. Flashed OpenGApps Pico.

Booted into system. Root available. GPS working (real fast first fix), bluetooth working. SIM and mobile network available. WiFi working (actually on fixed IP). Connectivity to Google servers and Google account ok.

Froze some of the Google applications like Play Store (I'd rather use Yalp), contacts and calendar sync (anyway, they don't have permissions granted to pass AFWall+).

So far, the system under "HWC" initially seems to work fine. I don't know (yet) why I couldn't get Magisk to run as SU. Just for testing purposes, I'm going to run the "HWC"-system for about 24 hours, especially to observe incoming and outgoing calls and to monitor a "reboot" behaviour) but afterwards I'm going to revert to my Nandroid-backup because I do not want to be stuck with Google!

Additional remarks:

Unfroze Substratum and PitchBlack, even rebooted. HWC obviously doesn't support Substratum. Immediate FC when trying to open Substratum (root granted to Substratum).

All my pictures I used to use as my wallpapers (I won't show any screenshots) are heavily distorted (only on start screen, not on locked screen). If I swipe through my screens the wallpaper briefly appears correctly but then remains distorted, actually not usable as wallpaper. Other wallpapers (except the mentioned pictures) appear to be fine.

UPDATE (2017-05-26): Running above mentioned RR version for nearly 24 hours. Extremely satisfied - besides being condemned to Google!

All (at least what I tested) running well and without any issues. Additionally to the above mentioned functionalities, I confirm that incoming and outgoing calls are working. Definitely no unintended system reboot within the testing period. I didn't observe any soft reboot and had no indication of one. Battery drainage is decent from my point of view (please see attached [nearly] idle dump from BBS). Beside my distorted wallpapers, no glitches, no flickering, simply a smooth running screen.

My overall impression: This RR version could become my daily driver if Magisk is going to work. Nice to have would be a running Substratum.