Samsung promised an official Ice Cream Sandwich ROM for the Galaxy S II which should land, according to the manufacturer, sometime this quarter, but we’ve recently seen an official Google Android 4.0.3 Ice Cream Sandwich ROM being leaked. We’ve tested out the platform refresh and found it to be really stable, fast, and smooth as you’d expect from ICS on such a device but in addition, Samsung is also adding an improved TouchWiz user interface as well as somewhat better battery life. (Scroll down for video!)

Those who already managed to take a look at Ice Cream Sandwich – either on their Google Galaxy Nexus or with the help of a custom ROM – know that the latest Android platform brings a couple of performance as well as user experience improvements. The Roboto font is quite nice on the Galaxy S II equipped with a Super AMOLED Plus screen and the processor on the phone just loves the latest Android build. Gingerbread was running quite well on the phone but those occasional hick-ups are now in the past.

Performance-wise the improvements are visible in everything that you do on the phone. However, we ran a couple of benchmarks to see exact numbers:

AnTuTu: 6257

Quadrant: 4225

LinPack: 46.992/78.05

SmartBench: 2517

To see the leaked Ice Cream Sandwich ROM in action take a look at our quick hands-on with the refresh in the video below – without it trying to be a software review.