The Galaxy Ace Duos runs Android 2.3.6 and that's gingerbread. I am not sure if there are going to be any possible upgrades to ICS or Jelly Bean given the limited hardware capabilities.
Obviously the Android is layered on top with Samsung's own skin and that's touchwiz. The question really is how does it perform? Is it smooth? Fast? Or does it stutter and hang sometimes?
So it has a 832Mhz processor which is the same as that in the Galaxy Y duos and Galaxy Y pro duos, but it has considerably more RAM. Galaxy Y duos comes with 290MB RAM and pro duos comes with 384 MB RAM. However, Ace duos comes with 768MB RAM I suppose and that makes it much faster than the other two dual SIM devices. So as expected, Android performance is better on this.
Screen Transition and Screen animations, Scrolling are all smooth and easy.