At the moment I find the UFO workflow overly complex relying on too many separate modules. Students new to type design hear the RoboFont buzz and think that is an easy way into the craft. Not. Installations cumbersome and then there are all this separate modules to license. I'll wait for FL6 which will invariably use a UFO workflow but it will be kept under 'one roof".
LOL, newest avatar even better :) If I ask 'whats up with that' on the forum I'm sure I'll be banned ;) I agree that the RoboFont + Others applications have failed in the market due to all the transaction costs, but it seems to me that Glyphs is taking the pole position that FL3-4-5 enjoyed for so many years, and FL6 will flounder because not enough people will license it to return the capital invested. Captain Seifert's ship has sailed.
I'm not so sure about your FL6 prediction. I'm bound by an NDA so I cannot say too much, but I am testing FL6 and the potential is astonishing. Glyphs one-monitor work flow approach has never caught my fancy and its interface is counter-intuitive to the way I work.