I must be the only one who thought the demo looked promising. Yes, the presenter decided to neutralize some guards but it was pretty obvious that it was a choice and not mandatory. Yes, focus mode is pretty OP but they explicitly state that it will be optional and can even be disabled if you lack self-restraint. The AI was the biggest area of concern, as it seemed a bit dumb but the game isn't coming out for a while so I'm hoping it will improve. The level design looked nice and open-ended and the visual style was very Thiefish. As for comparisons to Dishonored, yes, there are similarities. That's because Dishonored was very clearly inspired by Thief. If this game had no similarities to Dishonored, it wouldn't have any similarities to Thief either.
Easily the most annoying thing for me were the hand animations for interactions. I don't want to wait for animations to play out before I can collect loot or open doors. It was annoying in Crysis and I'm sure it will be even more annoying in Thief, given how much loot you'll be grabbing.