Here's my opinion on what's happened to PvP in the last couple of Minecraft updates.
PvP used to be about skill. Now, that is not the case, and I think this is mostly because of the sprint button being added, which I've said before on other theads regarding similar topics. Before the sprint button, the player that was quicker at double-tapping the 'w' key to sprint would get more hits and would generally be better at PvP unless that person was just worse at aiming their sword, which really isn't too difficult to do unless you have extreme lag. The sprint button completely took out a very important part of determining who was better at PvP, so the playing ground became pretty even.
However, on an even playing ground people needed new ways to get advantages over others. These advantages became the obnoxious techniques of rod-spamming, bow-spamming (which really came around once MCSGv2 changed the chests from having 1 arrow to having 5, but it got a lot worse around when the sprint button was introduced), and even teaming to make it easier to win (now called boosting). Another thing that people started to say determined who would win a fight is their ping to the server, which was never an issue prior to 1.7. (Seriously, I'm not kidding, no one ever said anything about ping until 1.7. Those were good times.) This is because being better at double-tapping 'w' simply gave more of an advantage than having better ping did.
Now that 1.8 has come out, hits have been very weird and honestly it does seem like it is based on luck. I'm not sure if this is the update itself or if it's MCSG's custom hit detection being really bad. One fight I'll completely annihilate someone with a combo and the next I get competely destroyed myself. Because of this the tactics that became popular because of 1.7 became even worse and more overly-used in 1.8.
Now, we are still in 1.8, hoping that 1.9 will maybe save MCSG from the dumps it's in right now. Who knows, maybe PvP will be enjoyable again in that update. However, I don't think that there's a way we can save the in-game community from how bad it's gotten, so no matter what MCSG will never be the same as it was in 1.6 and prior.