Just caught up to volume 42. Here are my thoughts so far on the continuation. (Manga spoilers)
I didnt dislike it, but didnt love it either. The main thing I didnt like is that very little happens. I've seen people complain about Guts, but I feel like its reasonable for him to be completely shattered right now. I really hope the director now isn't bullshitting when he says that he has enough details about the story moving forward that they will even have fairly accurate scenes and dialogue, but I'm certainly not expecting them to nail subtle character development and pacing the way Miura was able to. Long story short, I'll read 43 when it comes out and give it a fair shot, because I think its too soon to say if the continuation sucks or not yet.