Not that this is the smartest thing to do but...my 36 foot goose enclosed goes down the road at 12-13K lbs and I am perfectly comfortable doing 80-85 one hand on the wheel , lane changes are effortless, my 53 foot goose is at 18-19k and I slow down a little but still an absolute effortless pull. a 28 foot bumper pull although power wise is effortless the bucking and lane change require more attention to detail... my point being if you are going to do any distance hauling, get the goose.
But to Randy's question, If you can convert it, safely do so I don't think you will regret it.