It's certainly the most polished Yoko Taro game I've played. I've played Drakengard 3 and the start of NieR (the first one) and while they haven't been awful, but there's always been little niggles and periods where the game will chug badly. I had a couple issues of slowdown in N:A in the desert area, but apart from that I was able to maintain a solid 60 fps. Also, the movement and combat controls are so smooth.
If there's one thing I miss from Drakengard 3 that isn't in N:A, its the pitch black humour. I realise that it doesn't fit a game like NieR tone-wise, but some of my favourite moments in Drakengard 3 were the times the game lightened up an otherwise bleak story by injecting some humour. For example, early on in the game Zero (the main character) loses her arm in a cutscene. Almost immediately afterwards, the flower growing in her eye (its a long story) blooms and she grows a new body. Later on, this happens. [NSFW]
Also, this appears as a part of the cutscene after you defeat the first boss: