Delayed Mid-game Reaper

     In the earlier days of StarCraft 2 it was very popular to open 5 rax reaper. After a few patches that nerfed the Reaper, the trend seemed to die out. Nowadays the most we see is 1 reaper in the beginning or maybe 1 in the mid-game for some scouting.
     After some experimenting against Protoss foes, I have found a mid-game Reaper switch to be quite effective. This switch is most effective after or during an attack or some other pressure. Lets take a look at some facts and figures:

• Reapers cost 50min 50gas.
• With the 50min 50gas speed upgrade they are the second fastest unit in the game.
• They do 30 damage to buildings. (The same as a Thor which costs 300min 200gas)
• A Protoss player relies on pylons to power their buildings.
• Pylons have 200 hit-points, 200 shields.
• Existing Terran infantry upgrades from the Engineering Bay affect the Reapers building attack.

      By the mid-game most Terran players who are going Bio should have at least 1/1 upgrades putting the reapers building attack at a whopping 34. This allows 6 Reapers to two-shot a pylon. If the Terran player has a tech lab on 3 out of 5 of his barracks, within 2 production cycles out of those barracks he can have enough Reapers to two shot pylons. This becomes very effective with a bit of multi-tasking.
     What I like to do is: scan or send in 1 marine to scout their army. Then if I decide I can take them or at least do some damage, I send the infantry I have to attack their expansion with reinforcements rallying. While this is going on I hop my reapers into their main and take out the pylons powering their Warpgates so they can't reinforce.

     This either: does a lot of damage to their army and prevents them from counter attacking since their Warpgates are down and they are supply blocked, or its just a straight up "GG".
     If the protoss splits up their army, they will not stand a chance against the Terran army or they will lose their expansion. This is win win for the Terran. If they dont split up their army, they will lose their pylons in the main.
      I think that delayed Reaper multi-pronged attacks are something worth looking into for every Terran player who may be struggling against Protoss in the mid-game--or wants to delay their late game tech. The idea of, essentially, having 7 Thors with super-speed march into a Protoss base to Pylon hunt while you attack the front sounds good to me any day.