[GTStang]

What cam are you using? what are the specs on your cam card? It sounds like all the issues you are having are, MAF system inability to handle your cam within the stock parameters. So the Tweecer might be what you need, you just need to get a good baseline set-up before you can fiddle with it.
Oh and please make sure to include Cam Lobe Seperation. If you give me this info I will try to call the boys at Anderson Ford through my work. They will give me some good ideas to help you out. I wish I could help more but I have no real world expirence about the Tweecer. Because AEM is taking forever to come out with there unit for the Mustang. I may go Tweecer to so I'd like to learn about it also.