The good stuff: 

The user interface has been completely revamped and unlike the lipstick on a pig that was Gingerbread or Honeycomb which tried too hard to look cool, Ice Cream Sandwich actually looks good. Most of it is tastefully done and although it is hard to please everyone ICS is bound to please a lot more people than the previous versions of Android. Ugly is no longer the adjective that one would use to describe Android anymore. 

There are a lot more transition animations at work here than before but they all fit right in and at no point did I feel that the designers have gone overboard with them. As before, you have the option to disable them completely but now you can even control the speed of the animation. I chose to leave them on at the default speed as it makes moving through the UI feel a lot more natural. 

The new font – Roboto- looks good. I’m not a huge fan of it or hate it like some people, but I appreciate the change because this is the first time the font on Android has been changed since it was first released all those years ago and Droid Sans was never a good font. 

There are some new wallpapers both the static ones and the Live ones. The good thing about the Live wallpapers is that they can now be used without affecting the UI speed, although I’m sure they still have a greater impact on battery life than static wallpapers. 

The new lockscreen looks better and is more functional that before. You can also access the notification tray without having to unlock the phone first. 

Homescreen folders are a welcome addition. Android supported folders before but the implementation was quite terrible. The new method resembles the one on iOS, wherein you simply drag an icon on top of another to create a folder. 

All the built-in apps have been updated. The contacts app now shows large thumbnail images for your contacts, the camera app has a panorama mode for stills and a time-lapse mode for videos. The calendar app now supports pinch to zoom to let you see more details. The Gallery app is vastly improved. Gone is the horrible Cooliris gallery of the previous Android versions and replaced with a much slicker version. It even has an extensive photo editor built-in. 

The browser is much better, too. It’s a lot smoother than before and also incredibly fast. It also lets you sync your bookmarks with the Chrome browser for desktop computers. 

Text input is now much better and more precise. Underlines mistakes and offers replacements on double-tap. 

Built-in screenshot utility. Finally. 

The bad stuff:

UI performance on the Nexus S hasn’t improved. There is still that stutter every now and then. 

The Nexus S homescreen has a permanent Google search bar which is pointless as the phone already has a dedicated search button. 

You still cannot move around icons. If you’re confused by that statement, let me explain. In iOS, when you press and hold on an icon it starts wiggling and then you can move it around and the other icons move to make space for it. That does not happen on Android. If you have to interchange the position of two icons, for example, you would have to move the first one to an empty space, move the second one to the now free space and then move the first one in place of the second one. This, of course, becomes impossible if your homescreens are full, so you have no choice but to delete the first icon, move the second and add the first back again. Strangely, though, this works perfectly inside folders, as it does on iOS. 

You can’t move an icon across multiple screens in one go. Initially, when you press and hold on an icon and drag it to the sides, the home screens would keep moving till you reach the last one. Now it moves one screen and stops, till you move your finger and then it again moves one screen only. Makes moving icons across multiple screens a pain. 

Folders don’t name themselves. Google copied the folder creation method from iOS they might as well have gone all the way. 

The lockscreen lets you launch the camera but you won’t know that until you touch the lock icon. The camera icon is hidden until you touch and start sliding the lock icon. You also can’t change or add other functions to the lockscreen. 

The new widget system is terrible. It instantly gets filled with crap widgets from all the programs you installed and finding one the good ones becomes a lot more difficult. 

The new iOS-style horizontal paginated application drawer is pretty with all the fancy animations but not as convenient as a simple vertical grid of icons as in the previous versions. 

The new volume control bar can now also be operated by touch but it falls bang in the middle of the screen and blocks whatever it is you are watching. 

Gmail UI is a clusterfuck of meaningless icons and buttons. 

The browser is smoother but it does that at a price. When you scroll around the browser blurs out the page and only renders it when you stop scrolling. This makes the scrolling smoother but often you will be staring at a blurred page till it takes its time to render the content. If the content is particularly heavy it could take couple of seconds. On heavier pages the constant blurring when you scroll becomes extremely frustrating. Makes you wonder whether the boost in speed and smoothness is worth it. 

No smart dialing, still. 

No built-in voice recorder, countdown timer or stopwatch, still. 

The new pop-up menu uses a list view instead of a grid of icons at the bottom of the screen. The list items are a much smaller target and the lack of icons means you have to read the text every time before clicking on them, so you can’t just instinctively click on something. Third party apps still use the older method but it’s only a matter of time before they adopt the new view too. 

Taking screenshots is tricky. You have to press the power and volume down button simultaneously and the timing has to be just right or else you either decrease the volume or switch off the display. It’s nowhere near as forgiving as the iOS system. 

The ‘OK’ and ‘Cancel’ button position in pop-up dialogues has been interchanged. No idea why they would do that. 

Terrible battery life, although I believe it is just a bug and is likely to be fixed in the next version.