I can tell that the game was primarily designed with consoles in mind, and that's the reason why the PC controls feel counter-intuitive. And, yes, I had a few issues, but nothing to really take away from the enjoyment of playing. Some things I managed to fix by re-mapping keys. Others, I got help with here on the forum. The only issue that bothered me, and I couldn't find a workaround for, is the camera snapping back to the selected character instead of staying centred on the battlefield. I'm hoping they'll fix that in a future patch.
The camera snapping in tac is a confirmed bug, so it will be patched soon™. I remapped what I could (meaning nothing on the mouse because since when are mouse buttons bindable on PC games? Consoles don't have mice. That's just silly talk.), and it helped. I actually don't have any issues with the UI, but AoE loot and auto attack, both of which have been around for 16+ years are nonnegotiable at this point. BW even set the precedent by including them in both previous installments, so "we can't make it work" isn't a valid excuse. The only explanation is laziness and a lack of effort toward the PC port "development."
As for other things ppl have been complaining about with the PC version, I did not really experience them, or they did not bother me to a great extent and I just rolled with it. The game plays smoothly, no graphical glitches, no stutters, no infinite loading screens, no CTDs (you know... knock on wood). Character animations - they still look off, but that seems to be a tradition with DA, and they always made me chuckle. Tactics - I always played with them disabled. I micromanage every turn. Got used to that since Icewind Dale and Baldur's Gate.
So, yeah... overall, I had fun playing 
I haven't had any performance issues really, the game is buttery smooth any time I'm not in dialogue or a cutscene. Nvidia released a new driver today, so maybe that will clear up that issue. We'll see when I get home.
As for tactics, they're sorely missed. This is made worse by how completely retarded the AI is. You have two options for companions: uncheck the box next to the skill thereby saying "you can never use this skill, ever" or leave it checked thereby saying "if this skill isn't on cooldown put it on cooldown, always." This means that if you want your companions to do anything useful at all, your only option is to live in the half-assed tac view pausing every 3 seconds to re-issue the same commands over and over so your braindead companions don't stand in fire, attack random enemies, or (in the case of the PC) stop channeling the rift as soon as you switch away to micro some dip**** npc doing its own thing to start attacking whatever mob it was targeting most recently.
For your bit about ID and BG/BG2, the micro there wasn't so bad. Why? Click to move, box selection, and a camera that wasn't 5 feet above the characters' heads. Or, those games had none of the control scheme issues this one does because they were actually made for KBM.