First of all...just want to say that I loved the game. Currently going through some post-game depression as a result of how good it was. Regarding the ending, I feel they were all decent but had some small gripes about them:
Gripe #1: If you choose all of the 'good' options for Ciri, you are effectively being incredibly supportive of her and allowing her to choose her own path. This seems weird at the epilogue because you are convinced she should be a witcher. Earlier on, you were basically saying "do whatever you want to do" and happy with the result. I can only speculate that being a Witcher is what she wanted in the 'good ending'. In the Empress ending, it seems there is this sadness that permeates the entirety of it even though just a few hours before you were basically just allowing her to decide for herself and it's not like Geralt has never been at court (he was Foltest's bodyguard) and plus Ciri can easily travel through time and space.
Gripe #2: This one may offend some members of Team Triss, but I did feel that her leaving unless you basically asked her to stay even though Ciri was still very much in danger and she was supposedly really 'in love' with you, regardless of your choices at that point, that she would see Geralt's mission as more important than ferrying a bunch of refugees to a distant kingdom. Clearly these refugees are adults and could potentially speak for themselves upon arriving in Kovir. Putting this dilemma in play actually took away any sort of feeling that Triss really did care about Geralt (again, decisions aside). If you know the person you love is trying to save a "sister-like figure" and prevent certain doom, would you really need for that person to confirm your love before you would do it? I don't know. It seems a bit half-baked to me.
Gripe #3: No mention of Dandelion or Zoltan (these two especially given what they've been through in the last three games) in the epilogue. It was as if they were more acquaintances than real friends, which I feel is mistaken.
Gripe #4: This one might just be unnecessary, but why wasn't there any mention of what happened to the Lodge? Given that Witcher 2 is all about them and Witcher 3 is rounding them all up to help you with your mission with Ciri, but after all is said and done they just vanish. The only real mention of them are two of your potential love interests: either Yennefer living in the north somewhere (if you didn't choose her), living with her in some unknown location (if you did) or Triss in Kovir (if you did or didn't choose her), and one small nod to Philippa wanting to usurp Yennefer's position of being an advisor to Emhyr/Ciri.
Gripe #5: Why would Geralt retiring with Yen be boring? It might have just been a cheeky comment, but wasn't it true that Geralt wanted to leave the life of a Witcher and put down the sword before his murder in Rivia? This seems to be what Geralt wants the most. Not necessarily choosing Yen per se, but just settling down and leaving the path.
Gripe #6: This one is a bit trivial but I felt the Eredin and post-Eredin fight was extremely anti-climatic given his role--though sometimes more of a cameo--in the first two games. I actually felt the fight against Imlerith was far more satisyfing from a post-fight perspective than Eredin's fight ever was.
I guess that's it. I hope I'm not coming off as being too nit-picky, because I really did absolutely love the game, and I do realize there are so many variables to consider when crafting an ending based on so many decisions, but it did feel a little weird given some of these character's roles in previous games and how some of them were marginalized in the epilogue of the trilogy's conclusion.
1. Given the horrific history Geralt has with Nilfgaard, invading his homeland three times and committing countless atrocities to capture Ciri, it's easy to understand why he and Ciri feel that her becoming Empress is the "end" for them. It's also something Ciri doesn't want to do and is the sacrifice of her personal happiness for the arguable greater good. I don't think a "Happy Ending" for Ciri ascending the throne would fit the saga as it's not
Return of the King. Kings and Queens, with rare exceptions, are portrayed with a grossly cynical eye unlike other settings.
2. People who talk about Triss not being supportive of Geralt strike me as very troubling. Geralt spends a huge amount of time going after contracts on monsters, helping out locals, and interfering in the political process of natives. Why? Because he's a good person who can't turn his back on the innocent. Triss takes care of her mage friends by sending them to Korvir and then proceeds to meet up with Geralt at Kaer Morhen. From there, she's with the team even if she doesn't say much.
The only thing she doesn't do is go to Skellige with Geralt and we know that's because Yennefer was there.
3. Yeah, Dandelion and Zoltan needed an epilogue along with Priscilla. Something like, "Zoltan proceeded to become the King of Gwent and eventually became the producer of the cards, purchasing the company with money he made in tournaments. He is now richer than some Kings." Dandelion and Priscilla proceed to get married and he settles down (or not), too, as a potential ending.
4. I confess, I really was disappointed with the portrayal of the Lodge of Sorceresses because I think they royally backtracked on them. The Lodge, rather than Letho, were the chief villains of AOK and they were horrifically evil. The fact you have to make peace with them isn't a problem I had but I wanted to have a confrontation with Phillipa. I don't think she's a Neutral Figure but every bit as evil as Radovid.
5. Geralt leaving the Path is something he claims to want to do but, bluntly, we know that's not in his nature. Geralt ends up sacrificing himself to prevent a pogrom in Rivia because he can't turn his back on evil. Retirement is something I think isn't really in his nature.
6. I thought it was a fine fight but, honestly, think it would have been better to have Ciri kill Eredin. We didn't get a chance to kill Avalarch or the White Frost in a boss fight and that was cheap.