Entered the draft with this guy as the defenseman I liked most this year. Finished the season #3 on my list, after Reinbacher and Simashev through no fault of his but sheer progression/more exposure by the other two.
I like Gulyayev's skating, his ++ skill with the puck on his stick, his ability to manipulate defenders with fakes, his pugnacity, his arsenal of shots is pretty damned good, his release is more than fine, he takes some risks offensively but generally executes well and often on his gambles/cross-ice passes, and his ability to transition the puck both as a rusher and passer are very good.
So yeah, Gulyayev's potential upside is very high. If all goes well for him, he could be a Lubomir Visnovsky type of offensive defenseman.
But there is definite bust factor there too as Gulyayev's decision-making in the defensive zone can be a bit slow, he struggles to separate more physical players from the puck, he could stand to improve his angling and steering of players along the boards to more reliably gain/conserve possession, his pokechecks/hand-eye coordination are okay but not at the level required from smaller players for them to be very successful defensively, his gap control and anticipation could stand to be improved, and more.
Overall, I think Colorado did very well in the late first-round with both Ritchie and Gulyayev.