As was suggested, it is different strokes for different folks. The way you travel and he places you stay matter in this decision. And always, the budget is a factor.
For us and the way we travel, 4 down is best. It takes me about 5 minutes to attach or detach. And I have done that hundreds of times over the years. My car would not do well on a dolly, the angle would starve the transmission seals.
We towed our last car for 9 years, which helped spread out the setup costs. Hoping we can own our next toad for at least that long. We had Blue Ox on our last one, and the folks at that company are awesome. When we were at the factory in Pender, NE this summer, they took our 9 year old tow bars into their shop and refurbished them at no charge! New bushings and seals.
Besides Blue Ox, there is Roadmaster, which is similar but different. We have seen motor homes pulling a pickup with a cycle in the pickup, but have never noticed a trike hauled that way.
BTW, miles did not register on the car we towed all those years. Your results may vary.
Bad decisions make great stories!