Diff. Merge At Center - Collapse?

What’s the difference between them? Only difference I’ve noticed so far is the fact that Collapse can’t handle only 2 vertices. Why is it there? What am I missing here?

Hej,
merge merges ALL vertices at one point. Collapse handles each “island” separately. Try to subdivide a plane a few times, then select a few separate islands and try both.

Just read the ReleaseLogs!! All new features are explained there!

Ah, so if you have, for example 3 meshes in one object, the remains after a collapse will be 3 vertices.

http://img88.imageshack.us/img88/787/mergeji5.jpg