1) Federation Spawn
2) Ghost's Spawn
3) Good vantage point located between a stack of wood and some metal shelving. It's a great vantage point to both hills but mostly to far side hill. It's also great to pick off players standing on the balcony of the guard tower and has a good view inside the tower and on the stairs.
4) Well concealed location next to #3 but gives a full view of the guard tower's upper floor. It's a well protected area and almost completely blocks you from view of any sniper.
5) Using the tree stumps and contexual lean you can use this position to take over the hill. I don't think many players know that contexual lean works here because I rarely see anyone use it, but it's a perfect way to conceal you from your blind side while looking left at players coming off the far side hill and then looking right for players coming up out of the ravine. Though trees cover up most of the guard tower you might get catch some motion to help focus in on an unclear shot.
6) While most players rely on the construct of the guard tower to unsuccessfully cover them, there is a place located at the back of the tower where you can remain safely hidden in the shadows while still getting a good look out over the construction site and fully exposing the hill. Up on the railing offers a safe but advantageous view. It also catches anyone who comes up the ladder off guard.
7) Along the road there are trees and bushes that conceal your location while giving full view of anyone trying to go up the far side hill. It's almost 100% concealing. The little spot just around the corner is not only a popular spawn point but it's also a heavily congested area for those trying to take the far side hill.
8) Right next to an in-game spawn location this rock gives full view over the logging area but it also is a great place for a sniper to pick off unsuspecting targets trying to take the center hill. Thermal will also pick up anyone trying to camp in the ravine or inside the bushes.
9) On the side of the path leading up the hill there is a large rock next to some bushes. While concealing you this position gives you full view of the bottom of the hill as well as a good vantage point through the logging area. It also will protect you from anyone who might be sniping at #8. While I don't condone camping in this spot for a long time it will offer great flank defense for your team if they're stuck in a stalemate when trying to take the center hill. most players who try to flank up the path are too concerned with looking up the hill than to see you lying prone waiting for them.
I've recently found that Prison Break is a well balanced map great from almost any gamemode. There are so many good vantage points that are often overlooked and so many players are stuck in a routine of trying to occupy both hills that they're easy target practice. The only downside to playing this map is enemy airsupport. I find that helicopters and Trinity Rockets do very well while ground support is not so useful. Specialist is only as good as you allow it to be. While the pacing maybe slow, keep in mind that there's a great vantage point for any scenario.
Particularly points 3, 6, 7, and 9 are the most successful that I've found. If you choose to camp feel free to check out these points.
1) Federation's Spawn
2) Ghost's Spawn
Orange: Areas of caution
Magenta: Areas of fast movement
Just to note, some orange areas you might find safe and some magenta areas you could find dangerous, but as for personal experience I find that the orange areas are spots that I gets kills the most and spots I am killed the most. The magenta areas I find to be fast move, free flowing locations. If you're looking to make quick and easy travel or flank the enemy try to travel in the magenta.
Rushing on Prison Break can be tricky. Unlike some of the other rusher friendly maps I find Prison Break more about rushing to a good spot and holding it down rather than going non-stop for the entire match. If you were on the opposing team to me I would most certainly put you down several times if you tried to constantly run around. There are just too many vantage points that you will, at some point in time, find yourself running right into my crosshairs. So keep that in mind if you're thinking about going into full rush mode.
Flanking is a good tactic to use. As you can see in my first picture I've labeled some great camping and vantage points. You'll see if you compare those spots to my flow map that each camping spot also corresponds to a easily accessible route.
My advice for play this map would be to mix up pace and try to rush between any of these points. The map will move quickly as each team battles of the hill. When one team takes the hill they will most likely spawn on the opposite side near #1 and when this happens be sure not to get crossed up in the flip. As the battle ensues watch out for the enemy spawning in the top right corner of the map and the bottom middle. These two spots tend to be the auxiliary spawn points. The lumber mill and the middle left hand side are also popular auxiliary spawns.