Won this in the last quiz and got it yesterday. Thanks to all staff

Okay the very first impression:
Looks very cheap. Probably because of the five junctive places are obviously visible. And around the circle in the back have unfinished twisted chunk of plastic.
Also, first time in my life seeing a USB male part rimmed in plastic. When I handle it, it feels a bit brittle, making plastic sound and such. I have what I believe is a second gen R4 memory card reader with almost matte grey body and satin black cap and tail, and that feels much better than the one of AK2.

Once I inserted the cart into the DS, it wasn't that bad.
It doesn't have that round cut of R4, so it doesn't look that much like a flashcart. (Not compared to built-in memory flashcarts =P)
Also I noticed if I wanted to remove the memory card I have to eject the whole flashcart first.

I was gonna test it right out of the box (envelope in my case), but I just got the loader from GBATemp download section. (I don't know what bliss and whatever is =/)
Games like #2000 run without a problem. Loading seems to be a little bit faster than R4 on games like Summon Night.

Saves have .sav extension, 512kb but not exactly compatible with use in R4 due to the naming difference (R4 uses ROM.sav, AK2 uses ROM.nds.sav). You need to change the names manually before sticking the memory stick back in R4 family.

GUI offers bunch of things, easy to maneuver and well explained in most cases. (I think there's a readme of some sort that explains all features and how to edit config files and such?) From the start menu some preference setting was available but it looked like you'd need to edit the config file for advanced settings.

Homebrew DLDI patching works well as advertised.

Battery consumption is just about the same as R4. Fully charged it at 11p.m., played till 3a.m., a little more today morning and got the red LED.

Overall:
I don't really like the hardware of AK2's flashcart and reader, but the core of flashcart lies in compatibility. In that sense AK2 is better than R4, I'll keep the R4 memory card reader though =P

Note: This is not an entry for AK R.P.G. review contest.