Sometimes it is only Root that is needed to add functionality, or in some cases, remove it. Though more and more apps and functionality is available for non-rooted devices, root still has a lot of useful power: * Some types of backup require Root, so if you want a nice full, easy-to-do backup get root, such as Titanium Backup, which will allow you to remove the apps that are otherwise unremovable (once you have root access). * Some types of special proxies or device spoofing tools such as Market Enabler (good for making Google think you are in the US and not another country). On the other hand things like Orbot (a TOR proxy) can work without root * More direct manipulation of Android via shell, scripts, etc. * Handy things like volume control which starts at bootup and is an overlay on the screen. Necessary for devices with no hardware volume control such as the Kindle Fire. * Replacing fonts to support things like Khmer script (ok, maybe a limit case but still, it works).
CyanogenMod Custom ROM features
- CM has a great feature for my HTC Desire which allows it to use a part of the MicroSD card as RAM, so that the phone allows me to install (and run) a lot more apps. Basically HTC Desire is somewhat crippled by its internals (512 RAM/512 ROM) and using S2E basically extends the usable life of this phone for another year or two.
- CM is just faster, it manages memory better, and can overclock and put min/max settings on the processor.
- More control over the interface including useful things like using the top of the screen as a dimmer switch on the backlight. Essentially once it is configured, using the phone is faster because of the ability to customize aspects of the interface, including how the various hardware buttons perform (e.g., hold down home button to get list of recent tasks used, hold down back button to kill current app (remove from memory).
- Custom launchers, themes, lockscreen customization, and also tablet tweaks (for tablets). All things tweakable means more power and getting an interface that is fast and fluid. Basically it makes the phone experience better. How much better? Way better.