I hope your don't mind Craig. I'm going to plunk this link down in the middle of some questions about Kevlar and Spectra thread and line.

The link below is a BYU paper on the use of these materials, mostly related to reinforcement fibers, but at the end of the paper there are tables of properties. Properties or Kevlar and Spectra

I'm still not sure of the UV sensitivity of Kevlar. I know sailmakers noted a problem but then Kevlar is used for lines in both parachute and paragliding wings. For now I'll stick with Kevlar as it is fire resistent, where Spectra "burns readily".