PROS: Long rusher who can corner successfully with good bend through the hips and the physicality to tilt around the edge track. Most successful rush attempts come with impressive inside shoulder dip and twist to immediately create rush angle from the outside. Will throw hands to swat/rip, but hands often are wild, with shaky timing and location. Can work within context of rush and alter moves/rush plans.
Flashes the ability to generate initial displacement with bull rush and has hit a snatch and trap as a counter move, but upright frame can limit power. Has the strength to stack offensive linemen in the running game and can reset the line of scrimmage with length to keep chest plate clean. Is a good hustle player who will make pursuit tackles.
CONS: Lacks requisite explosiveness and quickness to be a penetrating player. Doesn't threaten outside shoulder with initial steps off the line of scrimmage. Upright out of his stance and will false step. Lateral quickness notably absent when attempting to work hips from square to angle when facing offensive tackles. Despite length and power to stack, doesn't have the athleticism to get involved in tackles when runners come through the gaps. Can take good angles when defending space plays as EMLOS, but cannot close to make tackles on shifty ball carriers.
Despite strength to forklift offensive tackles, lacks functional mass to anchor and, when he loses hands, will get displaced. Tight ends often win or get to stalemates in both run blocking and pass protection. Bend is good but limited, and often cornering attempts will end with Gustin on the ground at or behind the peak of the pocket. Double teams wash him into oblivion. Can get reached easily and is late to feel blocks from outside of his periphery.