Utter...athletic freak. Size, length, leaping, 40.
I think people have him confused with Sean Taylor. He's not, unfortunately. Sean Taylor had what Obi does not; Hyper-spatial-awareness, and "Fast eyes" (or the ability read and react) at an amazing level. This trait, probably more than any, is the most important for Free Safeties in the NFL. Its the analog for premiere defenders in baseball's ability to "get a jump." Consider Kevin Kiermaier. Yes, he has elite acceleration and speed. But the reason why he is bar-none the best defender in MLB is because of his uncanny ability to diagnose the speed and trajectory of a ball moving through space, process the angle required to intercept, and instantaneously get his body to efficiently move on that line.
The knock on Obi is that he has "slow eyes" and that is what I've seen from him. His OODA Loop (what is discussed above) isn't even average. It seems poor. He doesn't move until the ball is in the air well, he doesn't diagnose the point of intercept (be it ball carrier, or ball, or point of reception) well, and then he takes inefficient paths to get there. Compounding issues is that his footwork isn't great (sometimes leading to laboring) when he needs to change direction and sprint.
I utterly hate this trait for any Safety, but especially for deep Safety. Yeah, he can make up for a little of that due to his size/length/raw speed. However, the difference between a 4.40 who reads/reacts below average and then takes inefficient paths and has average/poor economy of action to point of intercept and a 4.45 guy who is fantastic at all 3? That means the second guy's "play speed" is much better.
Give me Budda Baker all day. He's a Safety in the mold of Ed Reed (play-making, instincts, aggression through a tackle) but with slightly better measurables.