Seats in 330 are definitely 'the cheap seats' but with only three levels of seating at Chase Field, it's not that bad. Try watching a game at Great American Ballpark or Dodger Stadium where there are more than three tiers of seats. The view from the top level ends up being awful.
You can see still see the ball as it travels without totally feeling disconnected from the game. If you bring a headset with a broadcast of the game, it will help you stay in tune much better.
I was very impressed with how much room there was between each row. If one of your neighboring fans needs out to go to the restroom, you can just adjust your legs without having to stand up. Cup holders are at the back of the seats in front of you. Just be careful on the initial climb to your seats, the stairs are a little steep but not unbearable.