I don't have any direct experience. I have some anecdotal experience with that. Generally speaking, it's hit or miss. I have clients who have convictions for trafficking offences of cannabis who have no problem going to the United States. I have people who have merely been charged but not convicted with cannabis offences who are denied at the border. It's really left up to the whim of the individual border guard.
Unfortunately, it's a thorny problem. There's not necessarily a legal solution to it. It involves political change in the United States and it involves Canada perhaps taking a stand on behalf of its citizens to say to the United States, “Look, we're your biggest trading partner. We're your most important ally. We share a long border. Stop banning our citizens from entering your country for negligible reasons.”