I just entered Novigrad for the first time in my very first playthrough and by the lords, this city is absolutely massive. I truly hope in the next Dragon Age we'll be able to explore a city this scale. I remember when first entering Val Rouyeux, I was so excited but then I was immediately crushed when I realized that the tiny market square was all there was to explore. The city was described on many occasions as being incredible, huge and beautiful, and here we were...locked in a small square with 4-5 shops.
Another thing The Witcher 3 does masterfully well and which DA:I very much dissapointed me with was the music. Not the quality as I thought DA:I's music was very good but the way it was used. Exploring felt painfully empty and boring in DA:I due to the lack of music playing (though this wasn't the only reason). Oh sure, a small theme kicked in for 30 seconds before going dark again, but it just made it more frustrating. In TW3, when running around with Roach I get this fantastic atmospheric music playing around, making the exploration and the areas feel far more alive and it gives them personality.
When I read the developers removed music from areas on purpose to "allow us to listen to the fauna and the environment", I was left shocked at how they thought it was a good idea.