It's doing everything I was hoping it would with no issues, plus it has compatibilities I didn't expect!
As far as I can tell, any game on the Omega plays just like my physical cart in any device I've put it in - GBA, SP, Micro and Game Boy Player for the GameCube. I didn't expect it to be compatible with the Player, but it totally is.
It's a nice step up from my little RS-90 Retromini I had been using. That thing was a cool device with iffy performance, and the EZ Flash Omega is smooth as butter. It doesn't feel like I'm playing an emulator, if that makes sense. With some tweaking, I was able to carry my same save files from that system, too, which was an unexpected bonus.
It also plays GameBoy and GameBoy Color games, which I also didn't expect! GB games let you choose which color filter you want, too, which is fun.
My only complaint is the "empty" space on the back of the shell above the board. It has two big holes in it, which saves on plastic but looks cheap. When it's in the actual handheld or on a shelf, it looks just fine. It's by no means a deal breaker, and the clear red housing I bought makes this cart look slick, even with my one complaint. Now I just need to go find a decal sticker for the front of the cart!