My 2 cents: Do you care about handling? If you do, get the Signia!! But if not, and if you could occasionally use the 3rd row, stick with the GH.

Do you need >5 seats?

There’s no point in comparing cars that are exactly the same since the result will be a tie.

They’re similarly sized, similarly fast, similarly fuel efficient, and similarly priced. So for many people they’re similar in the most important aspects. You’re acting like cars can’t be compared simply they have different powertrains. That’s silly.