Torsions are quieter and smoother running, no springs to rust and sqeak. But have less wheel travel. Also torsions will sit lower, a great help when the overheight is close for those standard garage doors.
My last Eagle had torsions, very nice, but didn't like the fact that it would lift an axle off the ground when backing up the driveway at the curb. Too much weight put on the axle on the ground. They also don't distribute the weight evenly among axles.
Leafs with the equalizer link will distribute the load evenly between axles, regardless of tongue height, going over curbs or even the crest at the top of a ramp. Noisey critters though.
Ordered my new trailer with leafs, no regets.
Both have pros and cons