It's a fairly common practice and works great. I and many other members have tried it (using Ativan among other benzos and sometimes Z drugs like Ambien, Sonata, etc) with great results. Don't expect a "speedball" effect or anything because it just doesn't work that way. As far as risks it's a pretty safe combo but I have heard people claim mixing the two together can be more prone to OD if they take the benzo before the comedown because stims and benzos tend to cancel out each other's effect, some people continue taking more and more without realizing the strain the substance(s) are putting on their bodies. Their is also a danger of serious physical addiction when using benzos for any reason so don't use them much at all, but some say using them during comedowns increases the risk of getting hooked. So just be careful and you should be fine.
