Its not that tanks are OP or AV have become to weak now. Yes it seems that way now, but its the lack of the right equipment and vehicles that create this inbalance. A tank should be powerfull and feared by infantry. It does not mean it needs to be indestructable. AV should make an impact, that does not mean it should be able to take out tanks with one or two hits. The balance lies in what is available and what not. ATM the balance is right, it takes multiple AV to take out a tank, sure it needs some tweaking but this is the way it is meant to be, no one man army's. As a matter of fact when they decided to rebalance the vehicles they should have introduced other means of warfare.

Next coarse for CCP would be to introduce Anti-tank Tanks, that have less effect on infantry and more on vehicles. Also the introduction of the MTAC and MAV, would give more roles. Different types of vehicles can have different types of roles. The logi LAV was the right idea, but they made the lav so that it can do everything, what they should have done was make it module exclusive, meaning only surtain modules can go on it and work with it. This is what they need to do with many vehicles, specialize them into surtain roles.

Next would also be a new look at the mining system, There should be more new mines, with different effects. To counter HAV, yet not make them one hit wonders. Meaning they would damage them severly, but would still need a hit or two from a AV weapon to give the final blow. Futher the infantry missile launchers, should be expanded beyond the swarm launcher and the plasma cannon, each with its own effects, including a heavy version, that would have more of an effect then a normal swarm launcher. the grenades would need more variety offcourse and the RE or booby traps, should be expanded to give each trap its own function. Some would be for infantry, some would work as AV, some are triggered, others proximity, shields/armor/ bonusses and negatives, etc.

The next part to balance it out is the survival modes. How can you avoid or escape the slaughter. Like the socalled barriers, that has been mention alott earlier one. these could provide a means of escape, EWAR to counter surtain systems, like radar jamming and targeting, Regeneration disruptors, engine blokkers, etc. Offcourse every action needs a reaction, so tanks should be able to have means of countering these things with other modules, what would in turn mean that given the limited space they have, they would have to give up surtain things like, the extra damage modifier or armor, what again in turn would make them more vulnerable to AV, etc. In other words you can't have it all.

These things would be the right balance, but as long as CCP refuses to work on them or just release them one at a time, instead of a complete package of many different things together. All we will do is go in circles, untill CCP realises that they need to start introducing these things to actually balance out the game and then in its turn break the circle.

CCP keep making these mistakes over, and over, and over.
Breach assault rifle.
Tanks.
Laser rifle.
TAR.
Calogi.
Flaylock.
Logis in general.

Now tanks again. Every major patch CCP screws up. I really don't know how they manage it - they're very talented.