The terminology is confusing. "Cycle Truck" = Schwinn term for a low gravity bike- bike with small front wheel, and big basket or box over the wheel. See the Worksman version.
"Long" sounds like you mean a bakfiets, with the wheel out in front of the load, with linkage from the handlebars to the front wheels.
Both are trying to get the load a little lower and allow larger capacity than a standard bike. If you don't see a need, then don't get one.
Advantages: You can see the load, for one thing, helpful if you're hauling kids. Can possibly make the bike narrower as well. Low-gravity bikes and longjohns, are still 2 wheeled, so wheels track in a single line, unlike a trailer or cargo trike.
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