They all arrived 2 weeks later. The Skins I ordered is XS by online sizing chart, the feel is tight and perfectly fit. I ordered the smallest size (S) for Xterra because there is no sizing chart avalible, nor online information from Xterra official website. Fortunately, it also fitted me well, but not tight enough as Skins A400. They are generally same in size (so I guess Xterra is Asian size). Xterra sleeves are wider than Skins, and the material is thiner. That accounts for their difference in tightness. Both of them have 3D patterns. ButI found out only Skins was 3D cutting, Xterra's was just patterns. I was not supprise at the momnet because the Skins' price is 4x higher than Xterra. Xterra one was just a entry level comprehensive tights.
I'v tried Skin A400 in a 24k long run. It was tight and the support was amazing, especially in kness and ITB. The 3D cutting is great, every joint is free and muscle feel the support. I felt like to sprint when I was weraing it. I'v tried to control my pace but I still 10sec fast than before. And I could hold a steady running form & pace all along. I thought it not a bad idea to use it in stride improving training, beside hard run recovery. After run I did not feel the pain and soreness in the muscle, nor sweaty legs. Just great.
I'v tried Xterra Plazma Skin in a 8K cruise interval. It was so thin that I could not even feel its existance when I focused my run. It kept my leg cool all along the run. Despite the design, it still provide support to some extend. That is enought regarding its price.
Apendix: comparison table
