Our team, in general, tends to excel in fights like this where you need to actively soak a mechanic or move out with a debuff. As a result this was an easier boss for us due to the fact it plays to our strengths. Our biggest flaw in our kill was not realizing that the symbols assigned by BigWigs to debuffed targets changes as you move through the phase, causing us to do much more unnecessary movement in our early progression. Once we figured out what was going on with the UI it was an easy kill for us.
By virtue of the fact we are a six hour team, our time spent re-clearing heroic was really siphoning out a good chunk of our raid time. Now that we feel that the cost/benefit of clearing heroic is too low, we are spending all of our time in mythic progression, which has been a big boost to our progression time.
Subsequent bosses have been easier for us, but this boss in particular seems to really punish bad RNG and classes without immunities. Running Roiling Deceit away from the team during Surging Darkness, depending on the timing between when those two abilities can hit the raid make dropping off roiling somewhat more treacherous and unpredictable than we were anticipating. Outside of that, this is a really fun boss with a small dps check for beating the third wave of adds that we really enjoyed. I know the dps had fun blowing up the large soldier packs.
True story: We were so excited by the kill on our first pull of the night and ready to rush off to the next boss (Efficiency™) we ran off to do Vectis without taking a screen shot, and what you see here is from the next week's kill.
What a fun way to start this tier. What was interesting to us about Mother was we had options for how we could have approached the fight. One way is that we could have done the strat where you trivialize the add spawn by moving all at once and sandbagging in the second room while all your healing cooldowns come available again, and the other dominate strategy being that you can trickle through both rooms. Ultimately, though, we went with a strat that had the entire team cross the first barrier blowing all major healing cds, while then quickly moving teams across to room three akin to the trickle strat. The hybrid turned out to be a lot of fun to execute once we got the hang of it, and when it was over we turned in a performance I think we can all be proud of with the second fastest execution at the time we did it.
Successive clears by this method have been consistent and really great for the team.