I has a very nice looking interface with built in Moonshell (Media Player) and much nicer touch screen features. If you have an M3 real I suggest looking at the triple loader. It has 3 firmwares in it! (Sakura and Original, it also has iTouchDS but I've never found a use for it) The only problem with Sakura is that the homebrew support is really low so I use the original firmware for that. Once you install triple boot selecting your firmware is easy.
For Original: Hold X as it boots up
For ItouchDS : Hold Y as it boots up
For Sakura : Do nothing till it boots up
Sakura has a system where an NDS file called defaultx or defaulty will boot if you hold the correct button. Someone exploited this and make NDS files that load the other firmwares. Because of this if you boot into the Original or ITouchDS Firmwares, Sakura will begin to load, however it will notice you are holding a button and then load the right firmware, so make sure you keep it pressed down till you see the firmware you want starting to load. Personally the only time I don't use Sakura is for Homebrew and for Band Bros. DX (Because of it 8MB save file that Sakura does not yet support)