I find Arts to be an immensely important milestone for AFI as a band. But I think there earlier Punk stuff was a lot more... well Punk. I think Hunter talked about it with God called in sick. That's when they became a little bit more ballady. Art seems to work off of that with more depth.
I sometimes don't know how to quantify Black Sails and Art in my head. There's such a clear division between AFI as a punk band and has an alt-rock band. And this is where the division is. I love it for what it is, but it's neither Punk nor alt-rock it kind of throws off the balance somehow.
As a side note, I see a similar parallel with current AFI. Burials and the Blood album don't really fit in with what the band was in the 2000s. So I'm curious to see where they go from here.