I love this pick. Exactly the sort of high-ceiling guy Colorado should be targeting as they can afford to be patient and wait the 3-4 years it will take for Reichel to grow into his body. He has legitimate top line potential and if he's allowed to slow-cook another 1-2 seasons in the DEL, and then 1-2 years in the AHL I think he could develop into an extremely good player. He has very high IQ, and already put up 12+12 in 42 games against men as a skinny 17 year old. Once he puts on 30lbs of muscle he's going to be a high-IQ beast, and make a lot of GM's regret passing on him in the mid- and late- 1st round.
Btw, I think it's worth pointing out that although Peterka is probably ahead of Reichel right now (and justifiably drafted higher in your list), the fact is that Peterka has already grown into his body and has little room to develop physically, whereas Reichel is still very lightweight for his size and that will probably factor into him projecting higher long-term.
Peterka is indeed a bit more developed physically than Reichel, but he still has a ton of room to grow into. I could see him gain another 10-15 pounds of muscle, he's got a heavy frame and should play in the 200s, and he must really improve his balance to be more effective, so there is quite a bit of growth to go through right there. Reichel is much lighter than Peterka and he's got more room to grow, as you've said, but he is also naturally thinner than Peterka, and might not play at 200+ in the NHL, to put things into perspective.
The big difference between Peterka and Reichel is the skating. Reichel is a good overall skater, not great by any means, while Peterka is amongst the very best in this year's draft. Skills-wise I'd have to give it to Reichel (though Peterka's stickhandling is awesome), same with the hockey IQ, but Peterka is relentless and forechecks, backchecks, pressures the puck carrier better, goes to the dirty areas of the ice more, and is just tougher to play against all-around.
If both reach their ultimate upsides, Reichel is probably maginally better, and a top-line forward as you've said, but Peterka has a lower bust chance and bigger chance to reach his potential, hence the higher ranking.
Even if Peterka fails to reach his potential, there's a good chance he is still a third or fourth-liner for whichever team drafts him. Inversely, if he hits his full potential you're looking at a 60+ point player that plays an incredible up-tempo game and makes life miserable for opposing defenses with his speed, puck handling, deft passing and pugnacity.
