XMI export, which version to use

[skiwi]

When doing a XMI export two XMI types are offered 1.1 and 2.1

The default appears to be 1.1.

Which type should I choose?
And why?

TIA

PS I note from the help that the compare diff utility only works on 1.1

[Geert Bellekens]

I think it only depends on what you want to do with the xmi export.
You've answered part of the question yourself, if you want to use it to compare model/packages then you want to use v. 1.1.

Geert