Well, I have an AK2 and an EZ-V, so I'm relatively qualified here. It really depends on what features you need. The EZ-Vi is super ghetto and hacky, but it has stuff like real-time save and in-game guide. The Acekard looks a lot nicer and most likely has better compatibility. Personally I use both, but if I had to sell one, it would probably be the Acekard, even though it's my main card right now. The EZ-V's features, while badly implemented and sometimes entirely nonworking, are a big draw for me.