The Adidas TechFit Powerweb short spandex is currently what I am using as my competition spandex (Track and Field - Sprinter). Adidas makes claims on their website and on the packaging that just by wearing this spandex that you will become faster, more powerful, and have more endurance. These claims turn out to be not that wild.
First off, I love the style of the Powerweb spandex. I've received many complements about how they look, so it's not just me thinking this. The quality of this spandex is great too. The only minor drawback would be that the material is on the thinner side, so it's not ideal for training in the cold. I thought the white with silver bands looks great for this pair of spandex. Another minor negative is that of course since it is white, it will get dirtier easier.
What makes this spandex so great is the Powerweb bands that encompass it. Adidas claims of making you a better athlete when wearing the Powerweb shorts are not that farfetched. The spandex is a little tighter than normal spandex but they are supposed to be because of the bands. That creates a minor negative aspect of these tights, that you can't really wear them for a prolonged time without them getting uncomfortable. Other than that, I love this spandex and definitely don't doubt that they might make you a little bit better of an athlete.
Overall, I would without a doubt recommend the Powerweb spandex to any athlete. I use them constantly and absolutely love them. They are also worth every penny that you spend on them.