I've finished TW3 several times and I got all endings. What I like about DAI is that there is a party and then the credits roll. TW3 goes a bit further. After the tower scene you are dropped back into the world and you see some of the changes there. But you are also given a mission to see what actually happened to Ciri and/or Geralt.
In my first playthrough I got the good ending and didn't know what to think of it. It felt a bit disappointing, until I saw that the game wasn't finished yet. The final scene with the sword in the tavern was simple, but way more emotional than the DAI party. Damn, CDPR are masters of their craft.
I didn't like the HoS DLC much. The story is just not my cup of coffee (not a fan of tea). It wasn't bad, though. Don't get me wrong. And it was still money well spent.
The BaW DLC was great, though. Again, great endings, atmosphere and story telling. There CDPR used the same idea, of the main story: You'll experience what the consequences are.
What I didn't like in the TW-trilogy is that some characters are showing up, without much of an introduction. I know, it is all based on books, but I rather have stories and characters that don't rely on another medium. However, I knew that TW was based on books before playing the games, so I knew what I was getting into.