I've said in other threads about Gilmour that he's underrated for his stints in St. Louis and Calgary, and overrated for Toronto.
Gilmour had great hockey sense, was a good puck-carrier and passer. His moment-to-moment play was very engaged, focused, and aggressive (simular to Clarke). Great awareness and smarts.
in Toronto, he carried the puck much more, became the heart of the PP, and just generally was a bigger star within the team. He fit their needs, and they fit his.
He was a bit lacking in skills, though....skating, shooting especially. Overall, he wasn't on a Fedorov level, even at his very best.
Another thing about those two seasons in TO....the NHL wasn't loaded with great teams at the time, which made the Leafs success easier.