Oh, this is hard. First I have to say that I am a sucker for colors like Weathered, colors that look differently depending how the light hits them and what you wear them with. Weathered has those purple shimmers that made me buy it, it also is a more grey than LL, which reads much more blue on me.
PS is much lighter, at least on me and although it is a very nice color, it does not change colors so much like Weathered does.
I am not sure if I like the texture of the Longwear shadows so much, but they are definitely good eyeshadows. I like that they have less of a metallic effect that some Veluxe Pearl eyeshadows can have, but still are not flat and Weathered still keeps this color changing quality. Weathered is an instant smokey eye for me and I have been wearing it a lot. Really depends how blue I feel.
I could not choose between them to be honest, that's why I got Weathered. If you force me to really only keep one, today I would take Weathered. But only if I really must.
I should stop now, I am raving. I have a feeling I'll be wearing Weathered tomorrow
Well, if you love Weathered, you should check out Howzat from Iris Apfel. I will still probably get Weathered as well and I like how these Prolongwear shadows have multidimensional effects, almost like Duochrome or microshimmers. I know I'd like the Weathered now better than LL since it is greyer and I will like the finish and the purple duochrome effects you are describing. See your description was so much better than a swatch b/c I am sure a monitor does not do these Styledriven Eyeshadows justice. It is hard to appreciate the multiple color effects I see with them. They are almost as good as MES (but without the eye irritation)