PV being overpowered is the weirdest misconception I have ever seen. Even if you ignore the fact that PV targets are invariably indicated on the motion tracker (including approximate vertical location), thus meaning you are sacrificing a newability for a redundant power, the fact is that it only displays foes you cannot shoot. Think about the balance of that combo. The reason PV is cool for some players, is that they don't have the situational awareness of high level players or observant motion tracker users.
This is where good-player feedback is so valuable. While you may not think its terribly overpowered, when you give higher-level players instantaneous feedback on exactly what their opponent is doing, it is overpowered. Radar at least has limited range and forces you to look away from your reticle and make an educated guess as to what the enemy is doing; PV bypasses all of that.
In a 1v1 situation, no other perk comes close to that. In team games, no other perk comes close to that. Also, radar isn't used in higher level games because it provides too much feedback and slows games down, now imagine good players in MM with PV.
Also, I'm thouroughly convinced that the in-house testing of Halo games is under strict Halo honor rules, where people use different things and play "friendly." Once you release something like PV into the wild of MM, its going to overtake everything else.
