It's so hard to find a reasonable comp for this player because he is pretty unique. I'm sure I'll get jumped for this, but he reminds me a bit of Alex Galchenyuk from his Sarnia days, though Demidov has better vision and puck skills while not being as fast in a straight line.
Neither guy was the quickest or fastest, but both were excellent on their edges, strong on the puck, deceptive & patient stickhandlers, and had great vision.
I agree with this 100%. Too often I see scouts hyper focused on skating technique instead of skating results. Yes, there are aspects of a players mechanical technique that can potentially give insight to the type of skater they can mature into, but more often than not, if a guy is getting around the ice really well, it really doesn't matter how it looks.
And beyond just fixating on skating technique, there is a real fascination with the aesthetics of skating, leading to the trend of "beautiful" (yet ineffective) skaters getting overdrafted (though I think that has actually slowed in the last few years).
I love Demidov's edges, balance, and control, especially as he slides laterally through traffic. But I would consider his agility to be pretty mediocre at this point. His footwork / footspeed are both relatively poor compared to his other skating attributes, and he can seem "heavy" on the ice. But I think this is more due to his poor posture & mechanics than it is an athletic constraint (meaning it's very fixable) - a few adjustments to help him get his chest up and knees out in front will really help.
I'm quite certain that with a few years of power skating and continued physical development, his overall skating ability will be plenty good enough for him to be able to take advantage of his gifted brain & hands.