I would be opposed to anything that overwhelmed the area and I've seen some performing arts centers that to just that - like Kansas City's:
I'm guessing there are some here who would love that downtown. But on Main Street? It would dwarf the area - even though there are high-rises around it. Sure, it would definitely have to be scaled down to even fit in that general area, but how does that change the dynamics of the style? It's definitely 'go big or go home' mindset that can work - if you're building it outside the city center (which KC has done, as it sits south of where their skyscrapers are located) - but on Main? It limits the options and while KC's definitely will have a wider impact architecturally than what SLC is building, unless we built the theater west of downtown, it just doesn't logically make sense to have something that large here.
Here's the Portland Center for the Performing Arts:
Ordway Center for the Performing Arts in St. Paul, Minnesota:
Holland Performing Arts Center in Omaha, Nebraska:
Blumenthal Performing Arts Center in Charlotte, North Carolina:
Aronoff Center for the Arts in Cincinnati, Ohio:
That's about all the research I can do right now. But those remind me of sporting arenas more than theaters and none impressive enough to say they're definitively better than Salt Lake's.