Re: cost of ownership
I drive about 15k miles per year. If I assume the 2.5L will get 26 MPG on average and the diesel will get 34 MPG, that's 577 gallons vs. 441 gallons. The current average price of 87 octane here is $2.31 and diesel is $2.50. That translates into annual fuel costs of $1333 vs. $1102, a difference of just $231. I typically keep cars until they become money pits which is usually 10-12 years, so if fuel prices remain where they are now I might just break even.
If fuel prices go back to where they were in the first half of the decade (~$3.50 for regular, ~$3.80 for diesel) the difference is $344 per year and I might break even after 7-8 years. And if the diesel ends up being a little more fuel efficient, like 36 MPG average, which is more like the VW TDI 2.0, then the payback time might be a year sooner.
Of course, if we were offered the CX-9's turbo instead for the same option price as the diesel, you'd never recoup the cost delta.