Thanks for everyone's input. I have only had leaf springs before and never torsion.

Rolls Axle Spring
 

Actually, I think that the Rolls Axle Spring is better than either torsion or leaf springs. They also make a first-rate aluminum trailer as well.

http://www.rollsaxle.com/

I have had both torsion and leaf trailers. My next trailer will definately be torsion. Zero problems with heat or weight distribution if set up properly. Zero Maintenance.

If you are looking for the ultimate ride check out this air suspension set up. I may try it on my one ton pickup this spring.
http://www.keldermanairride.com/

Steve