I never thought I would say this, but after reading Update 17 named items list I have to: Those stupid BtC Invasion Tokens are not worthless any more!
Last night my bard 22 went into Invasion. On Normal, because it was his first time (and first-lifer). First time took 30 minutes and maybe 10 Restoration scrolls. Second time still took 30 minutes but no scrolls. Third time took 19 minutes, and I don't think I can make it any faster, at least not without using up some hard-to-get resources. And then I looked at the kill count -- 119, and could easily get more if there were any point to it, -- and thought "If I am lucky, Update 17 will have Monster Manual 3. If I am really lucky, it will have reavers and/or beholders."
So the rest of farming is postponed.