Legacy aside, because it means very little these days, I'd say both matches are on equal footing right now. Main eventers have came down on multiple occasions to revitalize the midcard belts over the years, and even when that's not happening you have a strong champion like Miz, Ziggler, or Rusev who fit the division as hard workers who can get the attention on the belt.
To me it comes down to design. I hate how the WWE US title looks, and I don't think there's ever truly been a great design for the belt in it's entire existence. There have been 'OK' ones, but something about having to include the American flag makes the belt look extremely understated or overly tacky. The IC title is beautiful though, especially now with the white strap, so if I had to get pulled by customs at the airport and they were going to pull out one of the two belts, I'd hope it would be the IC belt because it looks less like a CAW league title and more like a legitimate championship.