From Promaster forums "A diesel showed up in Connecticut! 3500 cargo, 159" wheelbase. Test drove it today, as I've been waiting to do so since ordering a 2500 diesel window van in Nov.
There is noticeable lag when starting in 1st and it shifts to 2nd; the rest of the shifts were much smoother. Being empty and on a flat grade, it started off best in 2nd, which you have to do manually, but it's very easy, and then you can put it back into auto mode. Once you learn the shift points, you can ease up on the throttle at each one and then the shifts are very smooth, about the same as an automatic. That also made the 1st to 2nd shift much better, although I think the gearing for 1st is for heavier loads and towing, or starting on hills.
I only drove it for couple miles, but I liked it a lot, and am happy that I ordered one"