We're using Inception for our project and have added some extra features we needed. Hopefully they'll be useful for you too.
Added support for creating and updating media types as well as document types. It's called just like a content type, eg UmbracoCodeFirstInitializer.CreateOrUpdateEntity(typeof(FileMediaType));
Added support for setting the sort order on both tabs and properties
Added support for setting the description of a document type
Added support for overriding the default behaviour where the tab alias is appended to the alias of the property. This is necessary when extending the built-in 'File' type, which has properties like 'umbracoFile' on a 'File' tab which need to be recreated. 'umbracoFile_File' is not good enough in this case.
We're using Inception for our project and have added some extra features we needed. Hopefully they'll be useful for you too.