For me, benzos do seem to cancel out some of the edgy effects of cannabis, but it's sort of a catch-22.. It's a bit too much sedation for me (unless I take a ridiculously low dose of Xanax for example, maybe 0.25mg) and it tends to overpower some aspects of the weed high that I enjoy. "Typical"/moderate doses of benzos leave my mind feeling uncomfortably dulled, which isn't something I like to pair with the cannabis high (and for similar reasons, the tripping experience, but that's a different story)
I prefer using Xanax minimally for stimulant comedowns or occasionally by itself to chill out and get some rest after an extra stressful day. Makes me really wish I had some for later tonight, haha. (I'm speeding AND quitting my job in an hour, fuck me!)
I'm also gonna agree with those who brought up the it's-not-worth- the-risk-of-addiction assertions. (Though I think the risk could be dependent upon how often you intend to smoke and would thus desire benzos, and whether or not you have a steady supply of them)