The way I'd break down the positives are.
-Natural confidence and swagger. An easy leader.
-Makes multiple reads and throws to the open man. He'll distribute the ball rather than lock on.
-Short accuracy is better than he gets credit for. The big misses stick out, but his completion percentage doesn't lie.
-Doesn't wilt when pressure comes. Even after he spins out, he's still looking to throw.
-Pretty good athlete.
-Built strong enough to run regularly. Has power while running which is uncommon for a QB
-Arm's not big, but it's not a liability either. He can hit all the throws.
-Takes care of the football while passing. Doesn't force 50-50 throws or hero ball it. Very low INT percentage.
-Really, REALLY good at selling play action, which I think Linehan severely underutilizes.
-Throws an okay deep ball. Obviously he misses on a lot of deep throws, but 75% of deep balls league-wide go incomplete, it's a lower percentage play than people think.
The downsides I'd say are
-Doesn't "see" space well at all. Needs to watch a receiver separate before he pulls the trigger. Poor anticipation.
-Seems very average processing the game mentally. Doesn't call many audibles, falls into coverage baits teams leave for him. Zone kills him.
-Good for a couple absolutely brutal misfires every game. When he misses, he tends to miss high.
-Seems legitimately afraid to throw it over the middle, probably related to point #1 above.
-Not sure if this is Linehan or Dak, but he checks it down on 3rd down FAR too willingly rather than challenging the defense at the sticks.
-Doesn't manage collapsing pockets well. Either he spins out wide or he stands still. Doesn't know how to step up.
-Fumbles a ton when he gets trapped in said collapsing pockets.
-Poor touch on throws, can't hit stuff like fades.
-Holds the ball too long and eats some ugly sacks. Virtually never throws the ball away.
The way I see it, Dak will never be a Romo type field general, mostly because of that mental aspect. He's a good enough underneath passer and careful enough with the football to be a bus driver, but if we're going to roll with him, he'll need talent around him and he'll need to be managed. He is what he is, a bottom-half NFL QB.
If I was an OC, I would manage Prescott a lot like how McVay manages Goff. You're going to be a run-first team by necessity. Play action and RPO heavily off of that to keep defenses thinking, and use picks and screens to feed Dak a lot of easy one-read throws. When defenses start keying in on that, you can hit them with the run game. When defenses start crowding the line to play both of those, you can dial up some deep balls, assuming you have the WRs like Coop and Gallup who can separate deep from single coverage. This is why Dak sucked so bad at the beginning of the year, and why McVay pays so much for deep threats like Watkins and Cooks. Ideally, it would be sort of a Dak and Dunk offense like we saw in 2016, only with more modern passing concepts that Linehan refuses to incorporate.
The way to play Dak is the way we've seen a lot of defenses pay him. Drop your safeties down to stop Zeke, play underneath and "sticks" coverage aggressively, and take your chances over the top.