The next version of each smartphone's operating system is always the best. We impatiently wait for the latest and greatest firmware to come around, expecting it to liberate us from the shackles of last year's code and features that haven't shown up yet. This happens incessantly with Google's Android OS, andversion 4.0 -- unveiled at this year's I/O conference in May -- is no different. Known as Ice Cream Sandwich (referred to henceforth as ICS), the last word in the title indicates the merging of Gingerbread, the most recent phone platform, and Honeycomb, the version optimized for use on tablets. We knew this much, but were otherwise left with conjecture as to how the company planned to accomplish such a feat -- and what else the new iteration had in store.

But now the time of reckoning is upon us, and the Samsung Galaxy Nexus -- Android 4.0's mother ship -- is slowly spreading across the globe, its users being treated to this year's smartphone dessert. ICS is one of the largest and most important upgrades we've witnessed from Android since its humble beginnings, making a huge change in user experience as well as a massive number of bullet points on the list of features. Now that we've had the opportunity to take it for a spin, where does it stand in the ranks of mobile operating systems? Follow us beneath as we dig into the layers of this sweet sandwich.