The Marcus Camby similarities I think are uncanny. Both had late growth spurts, played for Calipari, are tall, gangly, skinny and exquisite shotblockers. Davis is a much better rebounder than Camby was at the same age but Camby grew into a fabulous rebounder in the NBA; at his projected peak, I don't think Davis is going to rate as a better rebounder.
Davis has the higher peak because his outside stroke looks better but it's a not shoo-in that he becomes more than an average scorer. He's shown glimpses of moves at Kentucky but a ridiculous amount of his points have come from alley-oops. He'd still have a monster impact because of his defense even if his offense isn't all that.
If he showed great passing skills, I could see the Garnett comparisons but he hasn't shown that kind of ability yet. He has Garnett's motor but Garnett's passing was a big part of his special package. I'd say Davis is a much better shotblocker though.