It was never an intention to update my firmware. I am completely satisfied with the stable performance of the Gingerbread (Android 2.3.6) on the Samsung Galaxy S2 on stock ROM.
But after positive feedback from peers, I bit the bullet.
And was I glad Samsung made it simpler.
All I did was to plug the phone to the computer, run Kies, who detects a new firmware, spent a lengthy time to download the firmware (depending on your network connection), then another short duration to upload the firmware onto the phone, and finally the bootup sequence where Samsung will optimise your existing apps with the new firmware.
When it’s all done, you have a Galaxy S2 running on ICS, with all your apps intact, save the homescreen launcher which is reset to default, so you have to set all the apps shortcut and widgets all over again – unless you are using third party launchers, for which you could backup and restore.
Tip: capture screenshots of your old stock launcher so that you can re-create them again after the firmware upgrade.
What has changed:
ICS improvements. You get the same enhanced apps and features as all the ICS-enabled phones. Like Gmail, Browser, swipe-to-remove notification, long-press home button for recent apps list.
ICS constraints. You also inherit the limitations. For instance, ringtone and notification volume cannot be independently adjusted.
Screen capture shortcut keys. Instead of the “home + power” button combi, you have to use the “volume-down + power” combi, and you have to hold it a little longer
Phone app. The contacts shortcut tab is gone. To access contacts from phone app, you have to open the menu.
Notification icons. They are now larger, and Whatsapp notification icon is in white, not in green anymore.
Restart phone option. You have option to restart phone when long-press the power button.
Camera. I feel there is slightly longer lag when I press the shutter.
Resume phone from standby. When I press the home button or power button, I feel there is slightly longer lag than previous.
Apps compatibility. Beware that some apps might not work optimally on the new ICS version, although occurrence is rare.
Overall phone performance. No remarkably improvement in speed, but no apparent lags either.
Update Firmware: Yes!
Ice Cream Sandwich is safe to update on your Samsung Galaxy S2. The update via Kies is painless and does not delete your apps nor reset any functions (except homescreen launcher shortcuts and widgets). All you need is about an hour of your time to download the firmware, execute the firmware upload, and apps optimisation process. Go for it!