If you go onto other online communities, they generally declare Downs to be as smart/instinctive as Reed, as athletic as Polamalu, and ok...maybe not the sheer size of Sean Taylor. But he's not any of those 3 guys. Those guys were One of a pool of just One (them) in college for doing what they did.
Polamalu has lots of highlights of him jumping over the offensive line to sack a QB or tackle a RB for a loss. That showed up in testing, his vertical jump was a ridiculous 43.5". Sean Taylor moved incredibly well for someone who was 6'3 and 230 pounds. Like the Derrick Henry of safeties. Reed had 21 interceptions in college, that's 3.5 times as many as Downs. In fact, Downs 2 interceptions this season were the only 2 passes defensed that season. He didn't get his hands on anything else. His two interceptions are, well, Grambling State QB not seeing he showed blitz then dropped into a Hook Zone, and a slow lob to a corner where 2 receivers were running routes way too close together for that type of throw. Downs did everything right on those, and his instincts that the QB wasn't going for the Quick Out but instead the Corner Route kicked in immediately. But neither show high level coverage play where his back was to the ball, then had to turn and locate it, or high point and fight a receiver for it.
There are coverage worries further down the field with Downs. He's still a really good safety prospect, but those that say they're worried he can't handle Deep Middle regularly, and might be just OK in Deep Halves have valid concerns. I know highlights aren't everything, but if all the highlights are him doing work in short/intermediate coverages and only one play even has him aligned in a deeper coverage then maybe Ohio State used him that way because he was much better closer to the LoS than further.
I like Downs. I think our defense would be better with Downs. But pick #7 is a bit rich for a position that's worth a little less, and someone that doesn't quite check all the boxes for unique talent.