As a preface I'm playing from Australia and thus have a 250ms ping to servers on the US east coast. I suspect this exaggerates some of the following issues.
The auto combat/harvesting system is working fine for me. The system never failed to put me in combat when I intended to fight. Every now and then it will put me in combat when I wanted to harvest though this is due to me being too far from the resource node. This could maybe tweaked further with taking into account if there is anything hostile in the vicinity. Though overall that new system works fine and feels much more fluid then the old Survival and combat trays setup.
On the classes I played around with (Frostweaver, Templar, and Ranger) there are instances where the game is not activating abilities when I press their corresponding button. This very often happens when I'm using the default attack (LMB) and then issue another ability. It feels as if the game was dropping my input because it was still executing the last action. If there was a short window in which abilities would be queued (if there is it does not seem to work in my case) this might alleviate this issue. With multi stage abilities like the Frostweaver's Free Weave and the Templar's Reproach in most cases the execution feels smooth but every few uses on of the follow up activations of the chain fail to register.
While there are these situations mentioned above where my input seems to be discarded and makes the combat feel laggy as a consequence, overall combat, ability execution, and movement feels fluid and responsive even with 250ms ping. I haven't done any PvP so I can't say how this experience against NPCs which live server side will translate to fighting other players it seems promising.
Looting of items feels laggy due do clicks on items not always resulting in them being moved to the player's inventory. I assume this is due to the server not permitting movement of items when another one is being moved and clicking faster on items then the latency to the server results in clicks being dropped. Having a "I'm busy icon" on the item being moved or better yet a queuing system would improve the felt responsiveness.
Interacting with corpses to loot them is very fiddly. It seems that the cursor has to be on a very specific part of the corpse for the game to recognize the intent and additionally distance seems to be quite crucial. This is made worse by the fact that the required point is not on the corpse itself but outside of it, see attached screenshot where the marker is dead center on the Centaur but no looting prompt shows up. In addition to this during the death animation/ragdoll of the enemy the loot prompt can flicker in and out of existence. Overall it would be ideal if the prompt only shows when the corpse lies still on the ground and the region to show the loot prompt is enlarged such that generally looking at the corpse will allow looting without the need to hunt for the perfect place to look at to get the prompt to show up.
Frostweaver's Crystal Lance has its projectile fly towards impact and impact in locations that do not coincide with the target. This can be only slightly off or also completely off. Even though the visual aspect indicates clear misses the game records and applies the damage, but it is visually very confusing.
Frostweaver's Volatile Ice Weave badly signals it's functionality, i.e.
While it causes damage in an area around it there is no ground target circle which indicates the radius visually, making it hard to get a feel for how close to a target it has to be placed.
When the Volative Ice Weave explodes there is a very noticeable delay between the spikes flying off and the target taking damage. This results in other spells being used and it not being clear if the spell actually hit something or not.
The attempt at reducing the number of clicks required to use ground target AoE spells is good. However, with the Free Weaving skills it doesn't work very well. I think in part this is due to the fact that there is no visual indication of where the cast will be placed making it very hard to learn the behaviour.
All mobility skills (right mouse button) seem to disable autorun if it is on which makes moving around clunkier then need be.
Templar's Censure leap ability fails to work in many cases due to colliding with ground terrain geometry. This makes it impossible to use the ability at any range if there is a slight incline or uneven terrain from the player to the target. This makes the ability much less useful on a class that already typically isn't mobile. Maybe increasing the arc of the jump would allow at least handling uneven terrain better.
The game does prevent you from swapping out abilities when they are on cool down. While this is a sensible and logical restriction the spellbook UI currently doesn't make this obvious. When a spell is on cool down it is shown as ready in the spellbook and dragging another skill on a skill currently on cool down simply result in nothing happening. If the state of skills in the spellbook were in sync with the game state then that would already make this clearer. Furthermore, adding a notification about this would ensure new players are not confused by this.
The links between zones on the campaign map are barely visible as dashed white on light gray is really hard to see.
Equipping consumable items such as bandages is non-intuitive. Simply opening the inventory shows no slots for items to be placed on the paper doll. One has to open the spellbook and then realize that the Alt+1 etc. slots are actually designed for consumables. This is something that people who do not watch the ACE Q&A or follow the development closely will not realize. Moving these slots to the Equipment page of the inventory where harvesting tools and gear are and labeling them as "Consumables" or similar would make the use much more discoverable. Being part of the inventory would mean players will see them the second they open the inventory and as everything else that sits in the inventory such as gear and runes can be applied in that part of the UI it would be sensible to try and drag consumables from the inventory to those clots.
The chain pull of Knight class enemies seems to work maybe 5% of the time it is being used making it feel rather useless.
Similar the shield charge of Knight class enemies barely every connects, maybe in 10% of the uses. I'm unsure if this is due to the AI not using it properly or desync issues due to my high ping to servers.