I watched SSY. I don't know how successful the style change was. /a/ and moonlanders are freaking out about it. They could have kept the character designs while still letting Yamauchi direct it however he wanted to like in Penguin Drum or Railgun so it was pretty bold move.
This shot (
http://i.imgur.com/GSGBt.jpg) reminded me of Hayama's drawings of Cyborg 009 character's on twitter. I think people would be fine with the style itself if it was done in a show that tried to evoke an old school feeling (like Casshern) and it's the drastic change itself most have a problem with.