Odds are good that Typica 2.0 will have a significant change to its main serialization. Most won't have to care about the difference, but it's both a significant reduction in file size and nicer for anybody doing by hand edits (though now that CRUCS exists, nobody should be doing that). Main downside I can think of is it'll break any XSLT workflows, but as far as I know, nobody is doing that. Might be worth asking the mailing list if it'll affect anybody anyway.