My wife has a 2014 2.0 MKZ sedan (AWD) and it seems to have plenty of power. I have a 2015 MKC 2.3L AWD which also has plenty of power - and in Sport is has even more power than needed. Strangely enough the 2015 2.3L MKC is averaging 26 MPG and the 2014 2.0L MKZ is averaging 24 MPG (by the computer calculation), so there goes the theory on better fuel mileage on the 2.0L vs. the 2.3L. I told my wife she has a "heavy foot" but she says not.
If I were buying the same cars today, would have made the same choice, as both are more than satisfactory and both have plenty of power. The difference in power (if any) is negligible. Coming from driving Infinitis for about 10 years, we know all about power and the new Eco-Boost 4 cylinder engines are very close in power to the Infinitis with their powerful V6 engines. More features: Infinitis with a V-6 get around 20 MPG and require premium gas. Our Lincolns with 4 cylinder Eco-Boost engines get between 24-26 MPG on regular gas. The fuel savings over a year are huge, with Lincoln having a superior advantage. Don't get me wrong - my wife and I both loved our Infinitis, but the Lincolns have a better and quieter ride, similar handling and nicer interior, some extra features, and at about $10,000 lower MSRP. Thanks Lincoln!
P.S. While others on this forum have reported some minor issues, our two Lincolns have been trouble free so far (other than the push button switch on the MKC, which was done quickly at no cost by our dealer.