Benzos are really good to have a round for the amphetamine comedown. I've been on prescribed benzos and amphetamines before, the amphetamine euphoria was lessened by the benzos in my case. That being said the amphetamine induced anxiety was eliminated and for me that was huge! I have pre-existing anxiety disorders and benzos always have been worth it, no matter what else I was taking at the time, as my anxiety is debilitating and I become the person I need to be if I want to succeed in this world when I take benzos. Idk I've known some people with Bipolar Disorder whose psychiatrists use a combination of Amphetamines and Benzos to treat them. Amphetamines cause some anxiety and if you have a pre-existing anxiety disorder then in particular the comedown from the amphetamines can be unbearable unless you have benzos to blunt the acute symptoms. I mean amphetamines and benzos taken simultaneously will impact the experience of taking them either separately or staggered. That being said you'll still get many of the positive effects of both chemicals and ya know it just might work out great. In standard doses I wouldn't worry about serious complications. If you are abusing them, I actually think adding the benzos to the amphetamines might make it safer. But what do I know. Be careful and pay attention to how your body feels and honor that.