I loved it. It's such a difference from the grim and dark main game. Although I loved that about the main game. I loved that the name blood and wine is about the story, but it can also be a hint to both the humans and vampires living there(The whole place is dedicated to making wine for the humans, but to vampires- blood is like wine to them.blood and wine~). I was also pleasantly suprised with the size of the dlc(although I should call it an expansion). Most 10 or 20 euro dlcs these days give you less than 5 hours of extra play time, this almost seemed like a whole new game. Hell, I think that blood and wine is bigger in size and gameplay than some full priced games out there atm.
I agree with some of the posters here that the difference in difficulty was a bit weird, especially the last boss. The last boss on easy was harder than any other boss on deathmarch, except maybe the frog prince. But maybe that is a good thing, since even on deathmarch after a while everything becomes easy if you level up right and use the right potions etc.
I also love the fact that, even after playing the whole game trough more than 5x atm I still find new things that surprise me. For instance, on my 7th playtrough I found the(spoiler) ,mushroom' quest where you can talk to roach and other animals. I really loved that quest, and it actually made me laugh.
I am still impressed with how the makers of this game take different countries/cultures and mix them together( for example, skellige being norse viking mixed with scottish culture). Blood and wine was obviously french and italian, and the sunny countryside together with much friendlier people(and knights sometimes rhyming lol) made for a really nice change in pace.
The blood and wine expansion also has my absolute favourite quest in the whole game. The quest where you choose to either visit the vampire elder or visit Syanna. The first time I visited the elder, which was absolutely awesome. The lore behind the vampires, or any lore in the witcher for that matter always interested me. I wish there was more info and lore on the vampires, like there was in Tesham Mutna(my 2nd fav place in the game). I had no idea though that the other choice would give me a whole other story and quest to follow if I chose to visit Syanna. When I did that quest and entered the magical fairytale forest, I was in awe. There were so many stories and characters that I knew from my childhood, and it was like I was 6 years old again. The first time there, I spent hours in the fairytale land. It is my absolute fav. place in the game, especially since I did not expect such a world in a game like the witcher.
The vineyard that you get from the dutchess was also a really nice touch, but I wished we has something like that in the main game. An upgradeable home, with armor stands and weapon holders to show off your armor and swords, pantings shields and trophies to mount... It was awesome, but I felt it was a little bit too far in the game to really enjoy those things to the fullest.
The expansion overall gets a 9/10 from me, but I may be a bit biased since the witcher is my all time fav. game. Seriously, it is so good that I find it hard to enjoy other games that I enjoyed before, because I compare everything to the witcher now. Until I played the witcher, red dead redemption had been my fav. game for years. I did not expect any game to push red dead from my nr. 1 spot, but the witcher did.
To summarize, the expansion had a few - points like every game but I hardly noticed them because everything else was so damn good and detailed.