[randywebb]

"they didn't seem to last in the sun up here at altitude"

- A very important point. Different parts of the continent have differt factors attacking the finish:
Intermtn. West - UV
SoCal - UV & ozone + other pollutants
PNW - water & moisture
E. Coast - lots of acid rain
Midwest - varies, not much acid rain (even tho it is produced by coal power plants there, it mostly blows over into NY, etc. before it precips. out)

So everybody has to do their own tests in their own location.