The update is said to be rather large in size, so you might want to do the needful and make sure that your smartphone is hooked up to a power outlet all the time, and falling back on your home’s Wi-Fi connection is a good idea as well, since you can never quite tell just how stable (or unstable) the cellular data connection is. Some of the improvements that accompany Android 4.1.2 would include Google Now and Project Butter, where the latter is more than welcome to make the user experience a whole lot more pleasant, especially when you take into consideration your ageing hardware.