spring axle upgrade or change to Torsion axle

My experience with 4 different leaf spring units is that the ride is very unpredictable. My current unit rides great even with an old fashion solid equalizer. But a previous unit was so bad I had Morryde install their IS system which is comparable to torsion axles. The change was dramatic. Another leaf spring unit did good with a rubber equalizer.

I've had two units with torsion axles and they both rode great. If I ever get another leaf spring unit that doesn't ride well , I will do exactly what you are considering. But I will get disc brakes as well.