No. TWRP and adb sideload
are both methods of flashing a ROM. None of my devices are A/B, so TWRP just works for me. From what I’ve read, I believe adb sideload
is the best way to flash A/B device but I don’t know for sure.
“Dirty flash” means flashing the new ROM over your existing data, using either method. This is what the 'Updater" app does with updates (and upgrades), so that your installed apps and user data are not affected.
“Clean flashing” involves getting rid of your existing installed apps and user data - either by wiping of formatting - before flashing the ROM. After a clean flash you do have to set your phone up again from scratch, either by hand, or by restoring a backup.
Sorry but I can’t - none of my devices have stable builds. And I wouldn’t install them if they were available because, from what I have read, there is no rooted debugging, so TWRP is the only functional way of making a restorable backup.
I use TWRP backup for backing up my current phone, but I need/use Android Backup and Restore Tools project for migrating between devices, because restoring a TWRP Backup
- is tricky - but not impossible - to do when the new device is the same model
- is not possible (as far as I know) when the new device is a different model
ABRT handles both those situtaions admirably. The only things it doesn’t restore is account data for apps like Mail (which allows you to export settings from your old phone and import them to the new one) and Account Manager. TWRP does that better.