Two quick points:
(a) Subject lines which accurately reflect the content of messages are greatly appreciated; they greatly improve the reuse of the TEI archives as an information source.
(b) TEI doesn't offer "predictable cutín'paste" as such. Certainly TEI-originated HTML and PDF tends to be survive cut'n'paste better than some other sources of HTML and PDF, but TEI also has shiny toys like <glyph/> and friends which let you introduce characters that aren't in unicode and can't be cut'n'pasted sanely in a cross-platform manner that I'm aware of. See for example the in-line images in http://www.nzetc.org/tm/scholarly/tei-Auc1911NgaM-t1-body-d4.html