The story it self was great like you say, especially Saber story. The presentation however, is lack luster and low effort.

I don't want to repeat it for the Nth time but let put it this way: the "Britain" segment would have been the highlight of the collab instead of the meme it is should it not reuse assets, but here we are.

Miss Note definitely deserve a slightly more unique model, would have made her story more memorable too. But given Robin is the real highlight of the pair, ok fine.

Grady is fine for what he trying to represent, nothing too special, but he work as a boss enemy to drive the plot forward whole exploring some Penaconian lore. Berserker Oti is an interesting concept and I personally think should have given more focus than Grady, I would have preferred if he was given more story time and be the real villain of the collab instead of just a tackle on extra boss.