I think that a lot of folks will tend to agree that:
- diesel does better than gas for serious offroading--both due to torque and fuel mileage;
- gas is significantly quieter than diesel when on the road;
- diesel gets better fuel mileage overall;
- gas is less expensive to maintain.
In the diesel category, many folks prefer the 7.3 over the 6.0 due to the issues associated with the 6.0, but there are plenty of folks who attentively maintain their 6.0 diesels, and are very happy with them.
In the gas category, many folks prefer the V10 over the V8, due to the added power available with the V10. Personally, I looked for, and bought a V8, and I wouldn't want anything else for my use pattern, which involves lots of pavement time followed by shorter stretches of offroad time.
I generally run 89 octane gas--always top tier--in my rig, and the V8 is smooth and quiet. If I need to get going in a hurry, I punch it and it picks up and goes. Personally, I don't need anything more than that. I will never beat a V10 in a race, but I don't use my van for racing. I get better fuel mileage than the V10, which--because I drive my van a lot--is a definite plus for me.
I was parked at the post office the other day. My V8 was running, but you couldn't hear it. A guy drove in with a pickup with a 7.3...that classic, manly, diesel sound. I can't match that. Then again, having a manly van is not one of my goals in life.
Instead, I want a rig that serves my use pattern, which the V8 does, about as perfectly as anything could.
I think the key, for each of us is:
- to pick what will work best for our own uses;
- to get the van that provides that un-measurable quality that, when we look at our rigs, makes us spontaneously say, "YES!" inside. As you continue your search, when you hit that YES, go for it.
Good luck--and you WILL be required to post photos when you find your rig.