I've pulled both, with trucks and a SUV. I've narrowly avoided accidents with each type. Personally I don't consider one type more SAFE than another, but the GN hands down, offers a very stable towing experience and a large interior storage.

The trailers will differ in their axle placements, and this will be one of the determinations of how much weight is placed on the tow vehicle. For the same box length, the GN will weigh more. It will also have a larger storage area, and can be very versatile with interior fittings. As far as a towing mileage difference, I have noticed little difference if the fronts are similarly shaped. However if the trailers differ widely in weights, and your towing is in mountainous areas, the heavier trailer would be a detriment. If you frequently travel open level roads, the aerodynamics of each would more contribute to or lessen the mileage.

I find advantages to each type, and even though we presently own only GNs, I would not be adverse to owning another BP. The biggest advantage of our GNs is the interior space advantage, and my being able to more easily hitch up the GNs by myself. Our BP trailers towed very well, and were equally safe in their operation.

You will notice a much more stable towing, when encountering strong cross winds or the oncoming bow wave of tractor trailers with the GNs. The GNs will have a longer wheel base for the same box length. This contributes to their stability. Their weight on the truck is over its suspension instead of behind the truck, which is more difficult to support and unevenly weights the suspension.

Your truck can tow each type of trailer. It will boil down to which construction will provide the better interior space and layout that you need.