I like FG more because it’s not dark (uh… kind of…) and I actually feel like I play something I like in general, rather than gameplay only. 
Although, I think the desert is in general too poor. It’s only a few main and side quests and Callagadra, nothing else. I’d want a new nemesis monster there, for example a scarab with a super OP shield that enables us to dual wield two handed weapons (there’s no error in this sentence).
The best desert area is Bonebleach Basin, unfortunately it’s ultimate only. I agree that it lacks side quests. I feel like the Mistress of Sentinels should give us some more quests.
As for the nemesis, I feel likeBeast Faction deserves one.
Lastly, not sure about that last sentence.
A shield that enables dual wielding two handers. It’s a cool idea, imo, because as long as you wear the shield, you can dual wield two handers, but it won’t be as OP as you think because when you equip a two hander the shield is put back to your inventory. 
#BadJokes
I like Forgotten Gods because it has bright colors, not only dark and grey. And the rivalising sects of the Witch Gods were great.
I don’t like the pathfinding in the city areas of AoM. But the worst is Port Valbury, it also has lots of frustrating aether tornados.
I definitely loved FG. I think it fitted amazingly into the story, like a twisted bad joke. What I mean: You have aetherials slaughtering your family infront of you, the cthulu-bois knocking on the door behind you offering you that you offer your blood, and while somehow staying alive some dickhead comes crashing into you with a green portal going like “Yo brother, those gods that never do a dang thing for us want u to kill a god that nobody cared about a century ago or we will all die” like we weren’t already about to die.
But yeah, gameplay wise it was a blast too. Only problematic thing about AoM was the malmouth slums and districts. God I hate stair, my character runs them up and down like 4 times before going into the right direction. if he would move at all when I click at another floor like crazy.
Also I liked to roleplay that I gave a damn about one of the witch gods, like “Oh yeah solael’s the best, man! The other witchgods suck! Sacrifice 4 life, literally”.
I loved more forgottenG because it is a bit less dark than base game, map are pretty overall, better boss encounter , movement skill ,life savior for farming.
Both are great but I can’t forget just how incredible the environments in Ashes were for me.
I felt like Ashes was an amazing experience in that going into such a large ruined city and the Fleshworks felt so claustrophobic, grotesque and exciting! The sound design in the Fleshworks was also great. The environments were incredible in a way Forgotten Gods really isn’t with the vast desert environments. However, still great.
Ashes of Malmouth <3 The environment, enemy design, and the plot point of finally attacking the Aetherial Vanguard sold it for me~
I liked chapters 1-3 of the base game, or more accurately up to Darkvale Gate. After that the game sort of seemed to lose focus, the whole Necropolis storyline felt more detached from where the game began.
The focus came back in Ashes of Malmouth and the lore stuff was a nice lead-up to Forgotten Gods. I just HATED some of the areas and enemies in AoM, which is why I don’t give it quite as high marks as I otherwise would.
Forgotten Gods has stunning graphics and I like it not being quite so grimdark, but a lot of the enemies there are extremely annoying. The lore in Forgotten Gods is excellent and really fleshes out a lot of things about the world’s divinities. Just wish the map had been completely separate instead of just an insert into the main map, because that would leave more space for future expansions even in the base map.
Story and atmosphere-wise I like AoM better, but I hate that you cannot access any of the content until you beat all four acts of the base game. That is incredibly annoying. You can access FG early in the game if you so desire. That should have been the case with Malmouth as well. If you went up there too soon and got your head handed to you, then so be it.
You can do that in the base game by repairing the bridge to Arkovia and exploring there without ever going to Burrwitch, so why not Malmouth too? They should have made the barrier breachable with dynamite instead of a quest item. I get that Ulgrim is tied into the AoM story, but if you went up there early, you simply wouldn’t see any of that quest line. Oh well…
I have really enjoyed the game in all it’s many iterations, even from beta, build 29, content completion for release of base game, aom, then FG…it’s all been a blast for me. Story-wise I do think that AoM was pretty spectacular, but all of the added content from FG probably pushes that over the top for me today.
I will be different, I liked FG way more… less green in my eyes, more soft yellow and some dark. Less annoying buildings, maze, blowing up kamikaze aetherials charging at you.
FG story also kinda intrigued me a bit, thinking that Korvaak even might not be that bad as Fleshmaster Theodil in Fleshworks area. So I have some form of understanding why he would do this, yet nobody is on the right track.
Shattered Realm is also really nice, can access FG content really early too. If I had to give rating for these two then:
AoM - great
FG - super great
In AoM, I’ve have better sensation, but I didn’t did the 2 in Ultimate yet (only starting ultimate 2 day ago). Definitely in love the Ugdenbog zone…