Effective some time in 2011, Miramax were either dropped by or dropped their old distributor (Disney I think?) and began releasing their catalogue through Lionsgate and Echo Bridge. The 2011 edition of Sin City has the same A/V quality and features; just a different distribution company (Lionsgate).
The content is exactly the same as the previous Blu-Ray release, special features and all, including all of the disc-based content on the Recut, Extended, Unrated DVD version. And it's still region-free, which is unusual for Lionsgate.