My feelings on Ekblad fall somewhere in the middle of the above two quotes. I don't think he's got Jones' potential like scott does, but I also think blinkman's really underrating his potential.
Re: the Jones comparison. Keep in mind that because Portland was deep on defense, that meant Jones didn't get the kind of minutes Ekblad does. Particularly on the PP, when their PP ran through Derrick Pouliot. Ekblad is his team's sole option on defense, so every thing runs through him.
Also, you can't underestimate the experience factor. Jones played his one and only season in junior hockey the year he was drafted. So it was essentially his rookie season, where he was learning the pace of the junior game on the fly. Ekblad's had three seasons to hone his craft against junior level competition, so his play this year was helped by having those 2 prior years learning experience.
There's also the "skillsets". Jones is a better skater. He's so smooth for such a big guy, so athletic that you wouldn't even know he's 6'4 the way he moves around the ice. Ekblad isn't slow by any means, but he's also not the skater Jones is. There's also hockey sense; Jones' hockey sense is, IMO, superior to Ekblad's. Ekblad gets by a lot more in junior based on being a man amongst boys, so to speak. Jones got by less on his physicality and more on his hockey sense/skating.
Re: Ekblad versus de Haan and Reinhart. I can't say for certain who will end up being better, as that would require knowledge we'll only have 10 years down the road. Having said that, based exclusively on their skillsets and how they performed at their draft age, and what that projects to, I think Ekblad's upside is greater than either guy's. He's better defensively than de Haan (at the same age), more physical, and has a rocket of a shot. And he's got a much higher offensive upside than Reinhart, while being a better skater, and not much below him defensively.
This is all speculation on my part based on watching all three at the same age (ie. their draft year). But I'd say Ekblad's somewhere in between where scott sees him and where blinkman does.