I haven't seen it in person, but I've flown over it a few times, as it's right on the flight path to LAX.
I don't mind it so much. It's gaudy but it's LA. It's going to look good at night when it's lit, showcasing the water and palm trees. It's not a stadium that would fit in the midwest or northeast. As far as the roof goes, it's translucent and the stadium is open air on the sides, so it will look and feel like games are played outdoors, but you can control the climate as well. Remember it's not just cold you're trying to keep out. Gets damn hot in LA and it's getting hotter.