Hey guys, fantastic work so far! So first, the game already feels great, has some epic juice in it and the design is cool!
Now about feedbacks: I'll re-use this thread to centralize things.

Game startup

The game takes a long time to load

Maybe due to the current build with debug infos activated (I guess), or the fact that there's a slow connection with the server (DSL only for the moment).

Act 1

First attack slow

I think this one is due to some first cache access for the anims/sounds/whatever.

Some popping objects

I remember a cut scene where the blonde character ("Val" ?) pops in front of the camera from a sudden scene change (like if she disappeared, then reappeared on that scene).
Edit: this seems to happen on many cutscenes, probably game object late loading

Overall attack feeling

Playing mainly with Diablo 3, in comparison, it feels like there's a small time passing for each attack, I don't know yet it's the animations, the sounds, it doesn't yet feels like a straight click > punch > dead feeling, like if there's some small delay (hard to describe).

Inventory Object focus

When we move the mouse cursor over an item from our inventory, we've got a popup describing the items characteristics. Now it seems that on certain conditions, when your open your inventory, move your mouse cursor over an item, nothing happens, but if you click once, then the popup appears (as if the inventory didn't had focus). I think it happens after a teleport, but I'm not 100% sure about that.

That's all I remarked until then: I'm already happy to see how the game progress turns out and you can count on me to make good advertising on it ;)