I have a 2010 Milan hybrid (same chassis as Fusion and Lincoln MKZ).

A hybrid "premium" price wasn't an issue since I bought it when the 2011's were out, after Ford announced the phaseout of Mercury, at the end of 2010 when the dealer wanted them off his lot (he had 6 left). I paid a LOT less than sticker and got a very nicely equipped car.

There are no performance/driveability tradeoffs based on acceleration. Handling, braking, etc is normal as compared to the 2-3 rental gas-powered Fusions I've driven.

I get an "honest" average of between 38-40 mpg in combined driving on regular gas. (miles driven/fuel burned, not what the readout says). My worst mpg was when the engine had to run longer in order to warm up the car to meet the climate control requested temp.

In an mpg-cents per mile comparison, the 38-40 mpg on regular would have a 10% premium over diesel due to the higher cost of diesel. Availability of biodiesel could mitigate that due to tax breaks, but the only biodiesel retailer in the 7th largest city in America closed so that's not an option (how's that for options). Stations near my house are about 50/50 with or without diesel. I can't assume there's a pump there.

In the Ford hybrid implementation acceleration hurts mpg the most. Stop and go is on the battery (unless you have a heavy right foot). Cruise on the highway and it's gas+supplemental battery.

I've changed my driving to avoid the congested and jam-prone freeways (abysmal sprawl in San Antonio) and get to work quicker on less gas over surface streets.

But if I was doing a lot of highway driving - I might consider a new diesel. I believe the strength of the hybrid is in the regenerative braking and the computer controlled shut-off while stopped, not on highway cruising.