Hi, here’s my feedback. 
I played CoF on launch and MG on 1.1.
CoF
Briliant, just need bug fix with dungeon boss drops.
MG
Search interface is lacking functionality - sorting items by affix rolls, was very annoyed to search items with good affix rolls - mainly felt this with idols - pick 2 affixes and then have to go through 20 pages of items that are bottom rolled. Needs more affix fuctions for example I want an item with t6 affix and some other one that can be t1 which I would upgrade in forge - can’t do that.
Favour. At one point I wanted 2lp boots from Arbor boss, could not afford ones at the market, so I chain ran dungeon. In the end I ran out of favour just to list boss uniques (did not interact with chests as I was saving for boots). IMO a player should never ran out of favour to list items from content he is doing.
Some live searches would be welcome otherwise I felt that I have to stand in market refreshing item list to get items I want instead of having fun killing mobs.
Harbingers & Aberroth
Harbies were fun just a bit redudant seeing same 2 models (maybe more different ones in the future?).
Aberroth - first impresion - THAT’S A BOSS! Later on just annoyed by how many DoT mechanics he has. Also in this case less would be more. Adding a number of different mechanics does not make boss fight better. Wines - uses once, red and blue ball dot - could have been one. Void ground - poor telegraphing as he uses same wind up as he does before the mini slam (unless that was the intention?), also very poor visibility at last part of the fight (dark purple on dark ground with dark purple beams covering half of limited arena).
Forgotten Knights
Ranks need reworking.
Ranks 1, 4, 8, 9 - cool no issues.
Rank 7 - completely useless.
Rank 2, 5 - simply does same thing.
Rank 3, 10 - also does same thing.
Every boss fight in game so far is giving us an extra reward (blessing from echos, dungeon mechanic from keys, eyes from harbingers etc) which creates a loop gameplay and there is no reason to repeat main boss in the game once you acquire his unique items (if you need one in the first place). With echo you can always chase blessing roll and raise corruption.
I think rank 11 from Aberroth would be great and some sort of bonus reward after fight - like insted of destroying the altar we instead use it to add something to our timelines, or interact with our gear (add 1 forgin potential or reroll rolls on an unique item).