We sat in row 6. These seats are good. My only gripe was how far from the field you feel when you sit here. I guess that's because the foul territory down the first base side is very wide. But we could follow the game very easily from here, I would recommend these seats to any A's or Raiders fan coming to O.co for a game.
The concessions were my other gripe. Having to stand in two different lines for two different items just makes it inconvenient on the fan. The lines were short though and the beer is still upwards of $10. With practically no restaurants near the Coliseum, you'll almost have to purchase something at the game so come prepared to spend some cash; you'll be there for 3-4 hours each game.

The stadium has pretty good access to the 880 Highway. There is a sign telling you which exit to take for the ballpark. There is plenty of parking around the ballpark, especially since the A's are often at the bottom of the American League in attendance. On some Tuesdays, you can park for free which is awesome since parking is usually $17. But I always take the BART to games, that way I don't have to worry about having too much to drink. You can park at the BART station near the Coliseum for free but some people aren't too comfortable making that walk at night.