Played the new version of devonshire today, gotta say I love the map now. The bottlenecked flag area and the outer door really make the map work for defenders. Next time I end up on the attacking side on that map I can give more feedback for the other side. It seems pretty balanced now though.
Played rochester today as well, and even though I hate walking upward for a minute, attackers were still able to win if the defenders didn't cover the chokepoints. This one seems a little more difficult for attackers to win on. I felt if the attackers didn't win on the first wave of attack that it would be too difficult to overtake the defense. Again, once I play the map on defense I can give a better outlook. It seems if defense spawned in the lower areas then attackers might have a better shot of winning (which they might already, I don't know all the spawn locations).
All in all, I like both maps and they are a welcome addition to the siege rotation.