It's a no-brainer......Diesel all the way.
Years ago they got a bad wrap because they smelled bad, were louder, and were not very suitable to cold weather. All that has changed. With the new emissions standards, the exhaust coming out of new engines smells about the same as a gasoline engine if the exhaust has not been tampered with or the fuel injection pump has been opened up. Back when I was at a job where I was in charge of buying trucks, I remember buying a new freightliner with a 450 hp Mercedes diesel and the exhaust didn't smell much different then a gas engine and that was back in 2004.
As far as cold weather goes, yes you have to blend No. 1 diesel with regular diesel to keep it from gelling, but any gas station that is serving regular passenger cars will blend the fuel at the pump so the consumer doesn't worry about it. I would imagine stations where you have to blend the fuel manually are servicing more of the Semi tractor type of customer who might or might not have heated fuel tanks so each customer would like the option to blend manually since he knows what he's doing. That isn't going to happen with normal passenger cars where the typical driver don't know siccum about the fuel itself let alone blending it for cold weather. Diesels are much less cold blooded now as well with the way the engines are made, the use of glow plugs and the fact that most have plug ins to keep the engine warm. I have a lot of customers who have diesel pickups and am amazed at some of the temps these diesels will start now.
I don't want a full sized pickup, but it I could find a smaller pickup with a new diesel engine, I would be all over it.