What current pick up do you have? and out of curiosity, if you're up for it, what will you be using the new van to haul around?
I've currently got a 2009 Ram 1500 Short Bed regular cab 4 x 4. It's the plain jane edition, with vinyl seats, rubber floors and crank windows. On a good day, I can get 14 mpg. It's a great truck and has been completely trouble free, but the gas mileage is horrendous.
I own a motorcycle outfitters shop in Friendsville, TN and use the truck for work and play. I can see myself camping in it from time to time instead of pulling my 6 x 12 trailer with me everywhere. I also ride trials motorcycles and feel that a van would be nicer since all my stuff would be inside and I could stand up to change, work on the bike, etc.
I've been looking at a ProMaster 2500 159" wheelbase high roof since the low load floor and front wheel drive are very appealing, as is the 25-28 mpg highway that many people are getting with the diesel. The Automated manual transmission lacking a torque converter is also appealing to me.
The Transit also has a few things going for it. I like the better build quality, the fact that it is taller inside (HR), and that there are more places to get it worked on than the ProMaster. The extended length is also much cheaper on the Transit than the PM. The downsides are that the diesel option is a lot more than it is on a PM, and being rear wheel drive the load floor is a lot higher, which is noticeable when pushing a 600 pound motorcycle up the ramp.
When the time comes to replace the current truck I'll go test drive both and hopefully there will be a clear winner based on my requirements, which will make the choice easier to make. Or make it impossible to choose,, who knows!