Choosing between MEF and MAF (System.AddIn)

Question

The Managed Extensibility Framework (MEF) and Managed AddIn Framework (MAF, aka System.AddIn) seem to accomplish very similar tasks. According to this Stack Overflow questio

Answer 1

MAF and MEF both can use AppDomains and both can load/unload dll in runtime. However the differences I have found are: MAF AddIns are decoupled, MEF components are loose coupled; MAF "Activates" (new instance) while MEF makes instances by default.

With MEF you can use Generics to make GenericHost for any contract. This means the MEF load/unload and component management can be in a common library and used generically.