I don't think we're really disagreeing here. I'm not arguing against diesels, I would have bought one myself if it were available. I drove a diesel Volkswagen van while I was in the UK recently; it worked quite well, got great mileage for it's size, and had decent power. Plus, I was originally looking at the Dodge Cummins diesel but the truck was about $10K more than my Tacoma.
The original question I responded to was are diesels better for the environment. As to biofuel, my only point was that as an environmentally-friendly fuel (as it's touted), biofuel isn't any better because there are other environmental effects besides greenhouse gases. With patroleum diesel you don't have the problem of huge tracts of land dedicated to fuel production, the biggest deal is getting it out of the ground.