TL;DR - I love the turn-based system on the whole and would choose to start PoE III in turn-based mode if it comes with that option.
I hope the devs will take some time to have some fun with exploiting the new options in terms of counter-play by making combat at the higher difficulties more punishing not by simply inflating numbers, but requiring the proper response to certain actions (interrupts, movement, prioritizing the right targets)
When I first played PoE II I felt its combat (and combat balance) was it absolute weakest point. On PotD I mowed through enemies, hardly ever taking notice of their abilities or intentions as the game didn't require me to, and didn't really give me the opportunity to do so. After revisiting PoE II with turn-based mode, I thoroughly enjoyed the combat even though the feature is still in its beta stage and not without its flaws. These are my thoughts on turn-based after doing my second run-through (on veteran difficulty, up to level 15).
+ The depth of the combat with the ability to counter/respond to whatever the AI is trying. Though perhaps in its early stages at this moment, the knockdown/interrupt counterplay is really fun. AI could in future builds punish harder for failing to adequately counterplay their attacks.
+ Resource management feels more intense and tactical as you get to see a complete picture every turn.
+ Positioning feels more deliberate. Again, the AI could exploit or punish this more, allowing for more tactical combat.
# The mode is very generous with free actions. these actions are obviously very powerful as they are all benefit and hardly any opportunity-cost, especially with no limit to the number of free actions per turn. A 'minor' action, taking 50% of movement or simply having just one minor action per round would limit their power and cause a little more consideration on using these abilities.
# AI - The AI still misses some actions on their turn and doesn't seem to consider sequencing or combo'ing actions at all. This would be a great addition to the turn-based system as well.
# Initiative - The transition from action speed to initiative feels fine if a bit blunt. Where action speed went from the most powerful and influential attribute to completely optional for most of the classes. Could require some finetuning to bring back the fantasy of having a nimble, fast-moving character rather than just the ability to go first in combat. (add movement speed/distance and disengagement defense as secondary bonuses of dexterity?)
# Weapon switching - should probably be a minor action, possibly alongside (some) potions and the second wind (atheltics) ability
# Turn advantage for the player - The players' party seems to get a free turn every combat on top of the movement advantage.
# Show enemy actions - Even more depth in the combat system could be achieved by indicating the unit's action not just when they are casting a spell. On mouse over it should show the action (by name and effect), its intended target (area indicator or currently selected target). This would further reward tactical play and allow for more punishing results when a player fails to respond adequately.
# Combat turn speed - I had the combat speed on the fastest mode all the time and still felt it could use a speed up, especially enemy movement.
# Pushing/collision - Sometimes units get shoved from their position by the pathing of other units.
# Out of range misses - Costly (melee) 'misses' often due to no fault of the player. As the system already detects why the 'miss' occurred but is also the 'cause' of the problem why not let it auto-correct by either providing the feedback before the attack or applying the attack as if the character was in range.
- Pulling unseen enemies/the entire room. This partially if not largely nullifies the positives on better combat control. IT's hard if not impossible to tell what enemies are 'chained' when you engange an enemy, often resulting in all enemies piling on the party, even where they didn't in real-time-with-pause.
- Enemy HP. The slower phase of turn-based combat makes it tedious at times to cycle through attack after attack while the encounter no longer feels threatening.
Overall, turn-based is great update and addition to the game! Can't wait for it to go out of beta and do another run-through.