ok so, I tested em both.
First of all, let's talk about AAS. The directories are good and it posts the articles quite fast. The account creation process is also a breeze so, I can say that it's a good software. However, it's very complicated, it's interface sucks. But, once you get all these setup, that is, once you create everything(profiles...etc), the submitting process will be just fine.
Now, MAS has got a great interface, the directories are similar(or, quite), it's pretty easy to use and it's as fast as AAS.
If I had to decide between AAS and MAS, I would go for MAS because it's got no drawbacks.
Hope this helps,
Jack