So, what, in your opinion, is lacking in DOS/DOS2, and how could it be improved?

Having played both, I hold the following opinions:

Story/Plot Execution: One of the weakest aspect of the game. There was a significant improvement between the 1st and the 2nd game, but it is still lacking, when compared to a game like Dragon Age: Origins. I am not really criticizing the main ideas of the plot/story, but rather how it is presented and executed. Dragon Age had quite a simple plot in essence, but it was very well executed, with multiple factions being involved, with their own agendas. The lore, the factions and the characters were all strongly interconnected. We can see, for instance, how the concept of the "Fade", the mages, the belief system and the actual plot of the game are connected, despite how distinct they were developed. We can look at the local politics, and intervene so that it help us fullfill the main plot. We see plenty of interesting NPCs, cool dialogues, camera angles and plenty of options to choose, from the lawful good guy, the defiler of sacred artefacts, to the absurdity of selecting your dog to be your champion in a deathmatch against the throne usurper. More interestlingly, all NPCs react appropriately to your decisions, up to a certain extent (e.g. a religious fanatic companion turning on you, while an asshole companion laughing loudly about your evil decisions)

Companions: This one was definitely where Larian improved the most in comparison to the first game. All companions have their own purpose, they all have some relevance to the main events of the game (besides being the chosen ones), and they are not uninteresting. While I find them much less interesting than companions such as Shale, Leliana or Sten, there is no question Larian has gone in the right direction. I can only hope that the next iteration will feature more companions with more distinct alignment and relationship with the world. The game should also feature party banter, so we get to be more connected with all the characters.

Combat: The one thing that Larian has no competition. I find DOS1 combat more interesting than DOS2 combat, due to the introduction of the new armor system. But DOS2 combat is still stellar. In terms of improvement, I can't really give any suggestions, as I think the combat of this series is pretty much the best there is out of any C-RPG, so there isn't much to compare. I do, however, think, that combat abilities should be somewhat more tied to the lore of the game. If you can use a Medusa's head, Medusas must exist in the game, and you should have the opportunity to fight them. If you can create wings and fly away, then I would like to see named NPCs using such abilities during story moments when it makes sense to do so. If you are using a High Level, rare-to-see spell, I would like to see people commenting on that, even during combat.

Character Creation/Progression: more face options. I like the current skill progression system, but I think perhaps less points should be available, so you actually feel a stronger trade-off between generalist and specialists. A single point in Pyro/Hydro gives you too much for too little investiment to simply pass it.