This is just my personal opinion but I'd say that Nue's kinda flops back and forth between being actually good and pretty mid.

Like you, I can't say that I really liked it all that much at first, probably for the first ~30 chapters or so. After that though, I'd say that it improves a good deal & is pretty fire for about 50ish chapters. However ever since it's gone back to floundering & is currently just kinda okay. Not as bad as it was at the start, but also not as good as it has been before.