What is easier/faster/proper way to bulk change issue type: bulk edit or bulk move?

[Błażej O_]

Of course we assume that source and destination project, workflow and screens are identical.

I'm wondering what are the real risks of both of these approaches, or if there is a big difference in performance between the above operations.

[Jeremy Gaudet]

I'd imagine you want to bulk edit; bulk move should only apply if you are changing projects or workflows, as you have to go through the wizard to map issue types, etc.  I don't know the actual performance profile of either, but changing a field is a simple update to the underlying table and a re-index, while a move should theoretically be a lot more involved.