Deciding to WSGI or Django for new web app
I've worked a bit with some django "apps" ,its really easy, but setting up the "apps" can be a bit of a long process.  Django has a lot of nice features that you won't be using and I agree that you might be on one "extreme" here.
I'm in the process of setting up a new web app and deciding whether to just do it with WSGI or go the full framework route with Django. 
The app's foremost requirements:
1) The app has no UI what so ever and all of the data is exposed to clients via a REST api with JSON. 
2) It will have data to persist so MongoDB & probably Amazon's SimpleDB will be used for the database side.
Is there a reason to use Django or can I get marginal speed improvement with WSGI only?
Previous server-side apps I've built were either with Java/Struts and Groovy/Grails on the JVM. My understanding is that Django is an MVC framework similar to Rails and Grails.
I've also played around with Google App Engine which uses WSGI as thin layer above your code for managing and routing requests.