I remember all the 139 skeptics 7 or so years ago moaning about the same things you are moaning about. After a little bit of work it was doing the job successfully and all the know alls had to get back in their boxes.
so we can look forward to the 189 being put into SAR service like the 139 with no night overwater capability because the SAR modes of the FCS weren't certified and the lighting wasn't up to spec?????
Oh and the 139 didn't have to prove how inadequate its ground clearance was for sloping ground (read mountain) landings whereas the 189 will!