It would be great, if while saving the file there is a option to save it as lower version's. So that, irrespective of my/your vendor's version; you can still use latest (2015 SP 1.1) SW and benefited from its recent advancements.
Least of it, this feature should be added for Service Pack's within same version. [eg: If you currently use 2014 SP 5.0 and still you can save the file as 2014 SP 1.1]
What do you feel ppl ???