This is a real tough call, but my vote is for Matej Tomek.
For me, it was pretty much a toss-up between Leier, Fazleev, Tomek, and Vorobyov.
IMO, Leier and Fazleev both look to have a solid chance as "modern" 4th line players. I've seen a few mention Leier as a future 3rd liner, which is certainly possible, but might be a bit optimistic.
Vorobyov is the big mystery prospect. I think he has to make this top 20 somewhere even though we have almost nothing to go on with him. It's pretty clear the Flyers had him ranked quite high and he was there big sleeper pick of the draft. It sounds like he has the traits of being a Couturier-lite type of player.
I decided to go with Tomek in part because he has the biggest upside. Although obviously he is also the biggest risk. The Flyers must have thought of him very highly to abandon there plans and draft a second goaltender in the 3rd round when he was still on the board. He has a good pedigree, will be in a great situation at UND going forward, and will most likely be getting great experience with Slovakia for the next two World Juniors. It just seems like he will be given ample time to mature as a player and is in a great spot to succeed.
I see a lot of people going Fazleev ahead of Leier. Leier was a better WHL player and had a good rookie season on the Phantoms. Fazleev came on strong at the end of the season but I don't think he should be ahead of Leier yet. JMO.
In defense of Fazleev, he hasn't been done many favors in Calgary. He is used heavily on the defensive end. His most common linemates last year were Sanheim's brother, Taylor, who is a fiesty little player but generates absolutely zero offense. The other linemate is Elliot Peterson who isn't very offensively gifted either. Leier on the other hand played on some damn good lines in his draft+1 and draft+2 seasons in Portland.