For me its primarily an economy thing, as a daily driver i would use my VX much more if i were getting better economy, i can allready hear someone saying that the extra 8 or 10 mpg would take a lifetime to recoup the minimum $2,500 plus its to cost to convert but i'm sure a good used 3.5 gas motor has to be worth $1,000 of anyones money? thus reducing the conversion cost.
And then there's the enviro friendly lentil sprout eating hippy feel good factor that you're being good to the planet. Whats that worth? Nothing to some people, everything to others. Crikey, i even re-cycle now (though i'm sure it all goes in the same landfill anyhow but it makes my girlfriend feel better which makes me feel better)
Its great that people want different things out of one vehicle and are able to do it. I once saw a Ferrari Testarossa with furry dice hanging from the rearview mirror, one guy looking at the car was getting quite upset about it, i thought it was absolutely hilarious !!
Pete