I love Lumen Field. I've sat in the cheap seats to the most expensive over the years. There's not a bad place to watch. I prefer the lower 300s rows A-M, for the atmosphere and fan interaction. I enjoyed the Kingdome in the early Knox era, but the "feel" of Lumen just exponentially exceeded it. ( I just miss the 3.00 "King Beer")
I've only been to two other NFL stadiums, not modern. Mile-High in the 80's was pretty intense. The fans were loud but still weren't smart enough to know to quiet down when Mr. Ed and the Donkeys were on the field. That place shook like it could fall down any moment.
The Los Angeles Colosseum was kinda of lame. I saw the Raiders and Seahawks in 1988. Both teams were contenders and there were tons of open seats. I was able to move up to better seating without being kicked out of questioned. The field seemed too far away and people seemed semi-engaged in the game. I couldn't believe Behring wanted to move the Hawks to LA. There were rabid NFL fans in LA, but the hassle of getting to a game, parking, driving home, and paying those high stadium prices for drinks and food were too much.