The HVAC company next door to us has a big fleet of these GM boxes. They're pretty commonly used for on-location services where a tech needs some mobile work space. Having vertical walls makes it easy to hang stuff and hold shipping stuff.
I was looking for a spare rug pick-up vehicle, one that would be easier for a non-trucker to use and with a lower step-in height. I did a comparison of the long, high vans from Promaster, Ford and Mercedes, and since GM doesn't make a long high roof I added one of these to represent GM.
The Merc was eliminated due to purchase price, cost of options, cost of routine service, cost of repair and too many stories about dealers that don't care how long the truck sits waiting for service. The Transit lost points for being skinny and for faulty Body Control Modules leaving people stranded. The Promaster won points for having the lowest floor step-in and also lowest street to roof height. It lost points for too many complaints about flimsy door handles and also having a faulty BCM that burns $100 headlight bulbs like popcorn. The GM box won points for being the least expensive and having the best reliability ratings, but lost points for having a foot less length. (Important to have a bit more than 12 feet when hauling 12 foot rolls of carpet.) I was concerned about the fuel economy difference, and then found out the biggest versions of the Eurovans get pretty much the same mileage.
We've have few complaints about our GM vans, and the guys next door said they have no big issues with theirs, so GM it is. Ultimately I decided we needed more floor space and ordered a 14 foot long box with dual rear wheels.
PS: Now that I know the single wheel boxes don't cost much more than a standard van, I might order a couple with side doors and install a
CDS. Just enough more room to haul tile and stone stuff.