Idk if gorillas are smarter, bears are very inteligent and cunning, they are known for that.
Although gotillas are as strong as 10 men, bears have got to have about the same strength, they are larger than gorillas. If it was a black bear, i would say gorilla, hands down, but grizzlys are BEASTS, have you ever seen one it real life, they are massive. Not to meantion their 5 inch knife claws and razor teeth. The grizzly is also a bit taller.