I personally love to mix a small amount of benzos with uppers because it lessens the paranoia and anxiety. For me that is a very small amount of benzos. What is your tolerance?
molly(MDMA) feels just like lorazepam or clonazepam to me they are hardly distinguishable from one another but that doesn't seem to be the case with most if you get a stimulating effect from molly then benzos will take the edge off of that and most likely make it a much more pleasant experience
benzo's will dull out stimulant euphoria ime, and may slightly decrease the psychedelia mdma will provide.
if you're on them daily and have a tolerance to them, you probably won't notice much of a difference as your receptors should be adjusted to the benzos.