I must say that I like the previous Metal. It's fun, over the top silly things that somehow because of the American Comic Book Writers way of writing, they made it like that it's actually something matters, even if it isn't. Like what Ascended said, it feels like Heavy Rock band of the 90s where it's loud, fun things that supposed to be enjoyed as what it is. While I think that the concept of BWL is too much like Judge Death and his dynamic quite similar in retrospect, I enjoyed his first few appearances, especially his first one shot and mini series. The same thing can be said with Perpetua and many other things. Have to be noted that I still didn't read Death Metal, because my country doesn't ship book in issues format so I am lagging behind you guys.
So if you ask me if I like BWL? I love his first appearances while the later when Tynion or Williamsons write him I don't like it.
Perpetua? As a whole she is interesting concept that should be explored more.
Metal? Metal is fun, over the top silly things that become matters because we are fans of the characters and the writers will it. I loved it for what it's.
The Mad Max World? I just say I kind like it.