Not sure about ICS, but Gingerbread on the Galaxy S2 is completely stutter-free. It took a while for Android to achieve this: I used 10 Android (company-)devices in the last 12 month, and even the Nexus S with Gingerbread would sometimes show some lag when scrolling through large lists. It was otherwise a very responsive device, and the lag is hardly noticeable unless you directly compare it with an iphone or an Galaxy S2. But there was some lag.
The Galaxy S2 is perfectly smooth. I guess it's the combination of the multithreaded garbage collector that came with 2.3, the dual core processor, and a very fine Android implementation from Samsung that solved the problem.
I also think that Android does benefit a lot from every MB additional RAM, because it gives both the application scheduler and the garbage collector more room to manage app lifecycles.
The Galaxy S2 is perfectly smooth. I guess it's the combination of the multithreaded garbage collector that came with 2.3, the dual core processor, and a very fine Android implementation from Samsung that solved the problem.
I also think that Android does benefit a lot from every MB additional RAM, because it gives both the application scheduler and the garbage collector more room to manage app lifecycles.