Typically a tri-radial will last a little longer because the orientation of the cloth is such that the stress can be better absorbed. Also, it should hold it's shape under sail quite a bit better for the same reason. I've raced with both symmetrical and asymmetrical spinnakers enough over the years as a trimmer (before the Admiral declared herself the official trimmer and demoted me to driving- I hate driving) to opine that I prefer tri-radials over radial/crosscut, but I've honestly never
cruised with either. That being said, I've only owned symmetrical chutes (that's what our one-design fleet is limited to) so I haven't done any
research towards
purchasing or owning an asymm. They are great
sails though!