Ideally, both UML14 and UML2 models should be maintained, but given the choice of on or the other I would prefer the UML2 version be maintained. Due to lach of multiplicity * capabilities in UML14 models for operation parameters and return types, as well as lack of unique checkbox for attribute/associations (which default to unique when migrating), models cannot always be consistent between the different UML implementations. Timetracker for example should have to change the Array datatypes to Type* collections.
Unneeded profiles should be removed from all models in order to minimize the number of exported model profiles, since MagicDraw exports all model references to a single directory and changes the exported xmi:id values each time, rather than referencing some standard pathmap variables and profiles reused between multiple models. Long term, we should keep the .uml models as the artiact of record, and migrate backwards to UML2.xml.zip and UML14.xml.zip if necessary (there are MagicDraw plugins to accomplish this).