Sure a AEM can do a lot more than a L8. But so can any other programmable after market ecu. I am not to thrilled about AEM, I used one on a Viper and they say it's plug and play, but forgot to mention that the battery light on the dash is not working any more.
Also it broke down for some mysterious reason, so I send it back. They said it wasn't broken, but changed something so my complaint would go away. That's either bad design or not telling everything.
The software they is use is fair to good. Some problems exist with decimal points.
However it TOTALLY NOT USER FRIENDLY. You need to be very skilled or have contacts with GEMS (the supplier of the PC software) to understand what the parameters do and how they should be setup.
Download the software from http://forum.aempower.com/forum/index.php (free) and see for your self.
A Pectel ecu is far better. But they are expensive. I am sure somebody can give you some advice about cheaper plug and play ecu's.