I haven't owned or driven one but have put several hundred thousand miles on I beam axle pickups over the past 40 years and that hasn't always been a piece of cake even though I've made a number of extended cross country trips. Rough ride, way less than great handling and they seem to wear out king pins a lot more often than you would think. I'd say that the biggest issue with swapping a straight axle or I beam under a car for the gasser look in the past has been with the level of workmanship and thought put into the installaton. In the 70's I saw some real abortions as far as straight axle installations went. Most guys who put a straight axle under a 50 something car aren't planning on making serious cross country road trips. I doubt we would see a straight axle 55 Chevy hooking up With Alex on one of his banzi trips to Austin and expecting to keep up with him. Most of those same guys aren't planning on using the car as a daily driver and a Saturday morning run of thirty or forty miles one way is a long trip for them. They will spend hours on end going up and down the street at 10mph on cruise nights connected to rod runs though. Truth be known would a well designed well built straight axle gasser style car with leaf springs ride or drive any worse than say a lifted Toyota pickup? Both the ride and handling are probably somewhat close to the same but the Toy may be a bit more practical in the long run.