To echo Andreas,

I'm using 4 mm plain dyneema for 4 years now and I'm still flying my 4 year old spinnaker. It is pretty much blown out by now, but the damage from the retrival line is minimal. I think I have about 15 small tape repaires in it. Mostly as a precaution as I also "repair" small marks to prevent them from ever growing into larger holes. I also found that the tape repair cuts down on new damage. The first few repairs you get quickly after that the tape itself seems to reinforce the problem spots.

Once a season I take my spi halyard off and wash it. This makes it clean and soft again and then reduced wear on the spi significantly. Other then that my spi halyard is out in the condition 6 months a year and will become hard with salt, sand and algae.

Wouter