Yeah Combat Metrics is the standard. The parse reports it provides are second-to-none. Just make sure to set a keybind for it once you've installed the addon.
Just "combat metrics". This got a update all time. "FTC" was good, but dont got any updates since a long time.
Use "combate metrics" with "constellations" and that can give you a feedback for your Championpoints, what you should choose. This is not 100% right, but very helpful for new player
I use combat metrics and FTC, one tracking the whole fight, one resetting when I stop DPS for a few seconds. For sharing DPS I prefer FTC over group damage share. Everyone seems to be using group damage share now, don't see why, it's awful in my opinion.