I've also been in this debate with myself. I think I've settled on a car hauler with 18+2 dovetail, slide out ramps and 5k axles. I also have low cars I need to be able to transport as well so it seems like a good compromise. My biggest delimma is wood vs. steel floor.
I just found a 7.5K dual axle dual brake 10 ply tire 18' with 2' dovetail for only (only, ha!) $400 more than a 16'/2 with 5k axles. 6" steel versus the 5" on the 5k model. Not a bad buy (from what I have seen).
But that throws another wrench into the decision. I had just about decided to get out of the 3/4 ton truck and get a max-tow 1/2 ton. But the 7.5K axles and 6" steel add another 500 lbs and make the trailer/tractor extremely marginal for a 1/2 ton truck. So better safety margin/value/construction and 3/4 ton tow vehicle versus 1/2 ton pulling more than I would be comfortable with.
And, it is wood floor with a steel dovetail. for $3400
I could order an 18/2 with the 5" steel and 6K axles which would weigh 500 lbs less (8 ply tires), but only $200 less cost than the 7.5K axles/6"steel/10ply tire model.
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Thanks for all the replies so far! I really hope I can get the tractor/loader/bucket/bushhog on the 18'/2' model. Probably the tail wheel will hang off (take off the tailwheel? and tie a flag? ha ha)