Let's be clear, I am a fan of malls. It's been popular since the dark cynicism of the 90's prevailed to disparage malls as camps devoted to shallow consumerism. Anyone who remembers being a teenager with no car knows the mall is a magical place where you can have hours of fun with your friends, and figure out some adult stuff, interacting with other teens and observing the adults.
That being said, the Forum is just a mall with some fancy stage dressing. It's no Valhalla -- or, to extend the Roman metaphor..... oh yeah, the Romans didn't have an equivalent to Mt. Olympus.
If you've come to Vegas to shop, it's a good mall. If you're looking for spectacle or people-watching, go to The Grand Canal Shoppes instead.