The thing with Sennecke is this;
The very thing that makes him unique (consistently beating Ds one-on-one, making high-risk plays and getting away with his because of his great hands), are things that nobody is doing in the NHL, unless you're called McDavid or Kucherov.
So you pretty much bank on him being able to fool guys like Charlie McAvoy and Jacob Trouba like he SOMETIMES does in junior without getting his head ripped off. That means you bank on him doing things that 95% of players in the NHL can't do. Or else, if you take that trait away from him (his ability to slip past defenders with a deke like it's nothing), there's not a whole lot of things to like.
His size? Well, he's definitely not a guy who uses it just yet. People are pegging this on "not having grown into his body yet". But you're putting a lot of chips on a VERY abstract possibility - him ending up using his physical tools accurately. Something a lot of players never learn to do properly in the show.
His speed? He's not slow, but I wouldn't say he has the speed to be able to stand out in the big league.
His engagement? Definitely not.
So what's left?
If the kid ever turns into something substantial in the NHL, it's going to be by playing a completely different game that he plays in junior, because there's no way in hell half the stuff he does down there works in the big league. Hell, it's far from always working in the junior as well, it's just that when it does it ends up in a highlight reels package.
To me, it seems like a lot of people are trying to talk themselves out of a very safe, rather high-reward, logical pick in Iginla for some reason. There are so few reasons to make a tough exercise like this even tougher.