I'm probably going to come back and fix this review up a bit when I finish the rest of the franchise, but for now, here's my review of .hack//sign.
This was a really enjoyable show but it definitely lagged in parts, and I also got the sense that Bee Train wasn't quite adept at dealing with Sadamoto's at style, because there are many shots that look off-model or strange (there's my two biggest complaints out of the way). I would recommend it if you like 2000s midbudget anime with strong concepts.
One thing that took me by surprise was that the show's tone was completely different than what I expected. Growing up the only significant contact I had with the .hack franchise was that my older brother owned two volumes of .hack//legend of the twilight. I guess I had sort of expected this show to feel similar to it, but it really doesn't. Make no mistake, that's to its benefit. I won't praise it too highly by comparing it to Serial Experiments Lain or Boogiepop, because it's much lighter than those, but it could fall under the same general survey in late 90s-early 2000s anime. It captures the feeling of playing a 3D CG video game from that time period perfectly, as well; it's oddly sparse and full of surreal landscapes.
I enjoyed the characters, but since this is part of a multimedia project and there are bits of that I haven't experienced for myself yet, I did find them largely falling a little flat (w/ the exception of Hotaru). For now I'll give it the benefit of the doubt on that and assume that the cast becomes more fleshed out.
The character design and art direction are a strong suit, though I think that the execution isn't always as solid as it wants to be. In particular I think a lot of the cinematography/scene transitions can feel dated, and there are a few experimental shots that don't really work (the only one that really does, though, is my favorite shot in the whole show).
The show's soundtrack is middling, with a few great tracks (those English-language vocal tracks are all stellar) and a couple horrendous ones (Sora's theme is annoying). My biggest complaint with it is that whoever was in charge of the audio mixing did a terrible job, because there are tons of scenes where the background music is so loud it almost completely masks the voice of the person talking (I don't know if this issue is present in the dub).
I know I'm listing a lot of complaints, but my thing is that while I do have many minor nitpicks about the show... they're just that, minor nitpicks. The foundation and concept of it are rock solid; it's just execution, execution, execution.
Also Tsukasa is cute and I support her and her relationship with Hotaru.