I have this, and I have mixed feelings about it.
It does NOT come in a GBA box. It comes in a DS box.
It also does not save your scores, which is a major bummer. I use the score saves to help me remember what I've done, and to try for better scores, and that's just not possible with the cart-based songs.
On the other hand, it has lots of great songs, including the song for Ashley's stage in Warioware Touched, Yoshi, and Mario 64, as well as some great J-Pop.
I honestly don't know if it's worth the $35-$40 it costs. It's probably something that I will go back to a lot, but it's also something I could probably have lived without. Unfortunately, you can't really figure that out for yourself unless you get it.
I don't regret the purchase, although I kinda can't. When I originally ordered Daigasso, I mistakenly ordered the Request Selection instead. Boy, did I have a nasty surprise when I opened the game case.