The only issue I see is that the motor is being put in a Focus. Not sure how the build quality will be, but the Focus is generally not the best quality or durability imho. For that much I'd opt for a Fusion Sport which is a much better platform, again imho.
I don't know about that. Again yeah the Focus starts life at a lower level and therefore they skimp in area's where Fusion is generally better at. But going from a 2013 Fusion Ti to a 2015 Focus ST (ST3). I don't see or feel a major difference. The Focus isn't noisier (cept when the engine noise is being piped in). The steers better. It's steering feel is better. It's ride is worse but that comes from a stiffer suspension than either the Focus Ti or Fusion Ti. The seat is better (well I personally prefer the Recaro's).
The downsides are only a single display in the dash, smaller MFT, less digital settings (accent lighting is a push button dial and not super configurable, and other settings like that). The passenger side doesn't get any electronics outside heated seats (manual adjustment and no lumbar). Those are things that they can include but would probably A.) Increase the price, and B.) create to much of blur option wise between models.
Actually over all I would say the Focus while again being targeted as cheaper car to start with. Is a better platform for performance then the Fusion. The rear is too light and even a only little hot on ramp speed in damp weather the Fusion was all to happy to loosen up. The Focus only loosens the rear end when you want it to (let up in gas mid turn) if you keep level and the car already has enough grip at the start it feels planted the whole time in every condition I have thrown at it. Again coming from the ST, and not a Ti, but it's short and stocky seems to be better made for fun. But ride and build quality don't seem to be that different between the two. If anything and having not driven a 2012 or older Fusion, if anything the platform on the Fusion might have gotten weaker or the Focus has gotten tons better.
But anyways the Fusion is getting a performance (Sport) model. But it will have the 2.7 TTV6 that the MKZ has.