Both these new maps are well designed and encourage tactical gameplay. The new map-specific weapons that are introduced are fun, but don't really alter the gameplay experience as much as the developpers would have you believe.
The Suljeva Cliffs level is small and suitable for no more than 20-24 players. Beyond that, things get too chaotic. However, it provides a great environment for small scale battles with a map unlike any other small levels in the game (in other words, it's a viable alternative to Radec Academy and Tharsis Refinery). It is long and narrow, meaning encounters with enemies with be quick and frequent. Catwalks between sturctures provide an oppourtunity to gain some high ground and a tactical advantage over your opponent.
The Arctower Landing level is arguably the better of the two. It's a larger and more complex level with indoor and outdoor segments. It does what so many other killzone 2 maps have done well, which is provide a vertical feel to the level. Several of the buildings have three levels, and using high ground effectively can help you dominate your opponent. One problem with this level is how easy it can be to pin the enemy within their own base if the teams are uneven. This can be fun if your on the winning team, and frustrating as hell if you're on the losing end of it.
The level pack is being billed as somethign that will "radically alter the Killzone 2 multiplayer dynamic". This is not true. The basics of the gameplay are not really changed. This statement refers to two new map specific weapons included in the pack. The Suljeva Cliffs level has a flame thrower and the Arctower Landing level has the boltgun. If you played the single player you will be familiar with both of these weapons. These weapons must be picked up on the level, and there is only one, so competition for them will be fierce. Both the weapons seem to be a little more powerful than regular weapons, but like any weapon they will require practice and skill to back them up. Because there is only one of these per level (in the middle), they are rarely seen. So their effect on gameplay is actually limited and you probably won't use them much unless you specifically go after them.