Well, AKAIO can't play music or DPGs. It includes a few nice features that Sakura doesn't have (toggle-able showing of hidden folders, built-in support for the 3-in-1, game and homebrew softreset... the list goes on) and has different looks.
The files are only displayed on the touch-screen rather than both, but AKAIO has a lot more skins availiable (and they generally look pretty damn good).

EDIT: Aurgh! I just realized that I was comparing AKAIO to MoonShell 2, not Sakura!
Sorry!

 

AKAIO is the main firmware for Acekards and although it is unofficial its a lot better than the official. The GUI and the layout is different for sure. AKAIO doesn't look all that close to MoonShell like Sakura did. It has a different look to it but its VERY easy to get used to. I switched from an M3 DS Simply to an AK2.1 and I didn't have any problems at all with the layout.

The way you boot games a different. I don't know if Sakura had RTS or SlowMotion or an In-Game menu but all of those things ARE NOT in AKAIO. Basically we sacrifice those features for 99.99% game compatibility. When AKAIO gets game fixes, we don't upgrade the entire firmware. Why should we, its only the game loader that's needs to be updated. So instead we update what's referred to as "Loaders". We get small updates very quickly rather than a large firmware upgrade at a moderate pace.

Although AKAIO doesn't get those cool features above, there's still somethings that make it unique compared to the Official FW. AKAIO can update loaders via WiFi straight from the Acekard, no need to remove the MicroSD. You can also update your cheat DB from GBATemp's Cheat DB and the Temporary DB. Along with that, AKAIO has Homebrew Softreset, Auto-DLDI patching, and much more.

You can find out more information here: AKAIO Wiki

 

AKAIO is very simple to install and use. Just unpack into the rood of MSD. All options are under the start menu (kinda like in Windows). IMO the M3 is more complicated since it has like what... 3 kernels that you can use, one is better for games, other for homebrews, etc. ALthough overall I think AKAIO does the job very well, but Sakura interface is clearly the best of the bunch. Game support/patches are faster on AKAIO though.

 

By the way you should give your M3 Real to your niece and keep the Acekard for your self.

 

Once I get my Acekard 2i in the next couple of weeks I can give you a direct comparrison as I am leaving an M3 Real to go to the Acekard. From what I've read though the Acekard is a better card.

 

six, but her dad usually does all the updating and stuff. as long as it's similar to r4 in loading games, I don't think she'll have any problems.
About the M3 and Acekard issue, I'm still leaning on the M3 just cause I have the perfect bundle.. I still play gba games from time to time, and I don't think the M3's expansion pak would work with Acekard's OS...
Hopefully, I'll get both when she gets old and quits being a gamer... or maybe she'll get both when I get old and quit... lol

 

r4 is no longer unsupported: http://gbatemp.net/index.php?showtopic=219894

 

Lol us Filipinos do that from time to time.. especially my mom and dad O.o

 

Give your niece wood and keep them both?

 

try both out yourself and then decide