I know we're on an enthusiast's forum, but if we ignore performance desktop, the process is actually really, really good for the two biggest markets namely servers and APUs where the efficiency at around 3.0GHz is actually almost ideal. Yes, the process was designed for ARM SOCs but with a good efficiency curve up to around 3.0GHz it is actually very good for server chips as well.
(from
The Stilt's Strictly technical thread over on AT).
Will be interesting how the 7nm process works out (those rumours of 5GHz+), but if the higher clock damage the efficiency a lot, AMD may have to do two designs for Zen+ one for servers and APUs and one for desktop and HEDT. Hopefully, by then they will have a bit more cash and volume to be able to afford this and for it to make sense.