In the list of changes in TeX Live 2013 it says
Prefer TrueType/OpenType fonts to Type1 when the names are the same.
But are not Type1 fonts better since they are vector fonts?
Can someone clarify why TrueType/OpenType are better?
All three font types are vector font formats, however OpenType/TrueType are rich formats that can support many more features and languages than Type 1 fonts can do, moreover, this change concerns XeTeX which can utilize these features, not any other part of TeX Live. This change was in response to issues like the following question: