I watched Brady Christensen's 2019 games against Utah (Bradlee Anae), Tennessee, USC (Drake Jackson), Washington (Joe Tryon), and Boise State (Curtis Weaver). I've seen his 2020 games against Coastal Carolina (Tarron Jackson) and Indiana (Payton Turner).
It's astounding. He was practically flawless in most of those games. I think I've literally seen him have one bad pass pro snap in all those games, against Payton Turner, who legitimately put a good move on him and got to the quarterback. That's it.
This would be a lot simpler if not for the fact that, when you look at him, he's really not much to look at. He's not got a dominating frame. He's really mobile but I wouldn't say explosive. He's got strength but it's not as if he's Mekhi Becton.
The difference between Brady Christensen and Rashawn Slater is that Slater got to face Chase Young on one of Young's (several) off days, and so people are taking Slater's resume more seriously. But neither one has better length than the other. Neither one has better strength than the other. And I'd bet Christensen is the better athlete. They're both very technical with active, disciplined feet, and really good hands.