The only disadvantage is the slight possability of bricking your phone. A true bricked phone is very rare, if you can get into download mode (hold 1 then hold power) you can get back to stock)
Watch the videos and read, read, read...
I would also suggest downloading odin and making sure your computer can connect in debugging mode and download mode. AFTER you have read and know a bit more.
To sum up totally with it.