Kernel is the heart of the Linux operation system like Android. The better kernel you have, the better performance you will get for you Android phone like Samsung Galaxy S II. So what is the benefit of using custom kernel? Most of the custom kernel will give you root access permission just like CF-Root. BusyBox and Superuser should be added too. Besides, ClockworkMod Recovery is also another must have component. In addition, depends on which custom kernel that you install, some have boot animation support, overclocking, undervolting voltage control, multiple tweaked governors, GPU overclocking, I/O tweaks, automatic backup of EFS partition, BLN support and more…