Much in agreement with comments posted so far, I'll add or embellish...
Holy smoke! Roll-up doors suck. First, you have to build around them, and second, on a dusty road it's amazing how much dust gets in the vehicle. I'v ereplaced my roll-up door but not the seals. They don't look bad, but I just might do it to see if I can cut down on the dust ingress. I'd strongly suggest swinging doors or replacing the roll-up with a wood framed wall and RV door. The only reason I'm sticking with what Ive got is that I plan to make the rear entry for a garage/shed only, so there won't be access from the cabin and it will be sealed from the cabin. Also, I plan to mount a motorcycle on the rear bumper, so I have to have a roll-up door.
Pretty much the number one reason I went with a step van is the easy entry/exit with the low floor height and the easy passage from the drivers compartment to the cabin. Another thing I really love in my step van is the view. As a motorcyclist I feel really deprived in the cab of a normal vehicle, which would include a box truck. In a step van, the view out the front is second only to a motorbike. Throw in the fact that you can just slide open the doors and you're practically outside driving down the road. Add to that the lower overhead clearance compared to a box truck and I was sold.
Step vans have, essentially, a skirt all around below the floor level of the vehicle. This allows quite a bit of unseen space below the sides of the vehicle to tuck away water tanks, gas tanks, water heaters and furnaces etc. I expect to quite a bit of cold weather camping so I won't be putting water tanks under there, but I know it's available for stuff if need be.
Oh, and I just think step vans look cooler than box trucks.
On the down side, step vans are LOUD! I'm sure box trucks are quieter. Also, the flip down passenger seat is basically useless for any time longer than about 15 minutes. If you're regularly going to have a passenger, you might have to go with a box truck. WHile I love being able to open the sliding doors while driving, the door pocket does take up quite a bit of wall space in the cabin behind. I would have put in a bigger, or more, window/s had I not have to deal with the door pocket.
Mine step van is 14' behind the driver's seat. I agree with 7Wanders this is a great length because you can just squeeze into one normal parking spot, but I would have really benefitted from an extra couple of feet behind the wheel wells for my garage space. C'est la vie.
Having driven U-Haul full sized box truck before, I have to say the experience driving a step van is quite a bit closer to vans and normal passeger vehicles. Yeah, you're higher up, but I would have thought it be closer to a box truck than it is. It seems the muscle memory and experience driving a regular van transfers better to a step van; a box truck just feels bigger than a similarly sized step van.
Horses for courses...your milage may vary...but I love my step van. Build thread in my signature.
