Interestingly, my ex-husband went to BK recently to try the Impossible Whopper (or whatever it's called). He was disappointed and said it was no different from a Morningstar Griller (original). Since that BK does offer Grillers, I said that maybe that's what he got and someone just made a mistake. He waited a few weeks, went to another BK and ordered the Impossible thingie and again got what he believes is a Morningstar Griller. Both these BKs advertise the Impossible burger, btw.
He called someone (corporate? regional? local store?...I don't know) and was assured that no one would confuse the two products because of blahblahblah. So...the questions remain... Is the Impossible burger that much like a Griller, or are these BKs selling Grillers as Impossibles for some reason (cost, etc.)?