Go to
https://seahawks.io-media.com/ it gives you a view from each section that allows you to scan up, down, and all around. You can look up to see if that section is under the roof. Way better than the static view most sites offer.
Hawks nest can be very cold that time of year. It's fully exposed to the elements, and has aluminum bleacher seats. Both end zones are pretty rowdy. Hawks nest is cheaper. South end zone is warmer, and equally loud. I prefer the latter.
Where you sit depends on the experience you are looking for. If you want to feel the energy of the crowd, and really enjoy the volume, the south end zone is where it's at. I've had my glasses broken, and my jaw dislocated there during NFC Championship Games. You will miss a lot of the action. For example, I had a hard time seeing the 2 point conversion in the NFCCG against Green Bay. But "The Tip," and Kearse's overtime game winner were both right in front of me.
If X's and O's are your thing, then Charter 307 to Charter 311, and Charter 333 to Charter 337 are the shit, especially if you get row 1. It has a more detached feel, though.
Club seats offer a more refined, hybrid experience. Somewhere between the end zones and the charters. It has a slightly less detached feel, and slightly less X's and O's visibility, than the charter seats, and isn't as rowdy as the end zones. The crowd tends to be quieter and less involved in the game. They sit down a lot. I felt a bit out of place in these seats, but still had a great time.
Technically, club seats are all under the roof, but, if there is a bit of wind, you need to get above row F, or so, to be sure you are out of the elements. You get access to higher end concessions, concessions delivery to your seat, etc.