Basketball shoes are form fitting shoes, so the idea of "sizing down" in a basketball shoe doesn't make sense to me. Either you don't know your true size and/or you're accustomed to wearing one brand.
In my opinion and experience, Adidas is more true than Nike. I wear a lot of running shoes.
I think some people confuse their Nike sizing with their Adidas sizing. I usually go up 1/2 in Nike models, TTS Adidas. They're snug, but that's how basketball shoes should be, maybe go up if you're wearing them casually.