I tried spectra for the trapeze about 3 seasons ago. I found that they vibrated in the breeze when the weight was on. In the end this was so irritating I went back to wire. I couldn't really see any important advantage in using spectra.

Maybe for a sloop with 4 trapezes up the mast the weight may be considered important but I would say one misjudged tack is going to be many times more damaging than that little bit of weight in the rig.

Of course for someone without a swaging tool it's much easier to use spectra.