It depends on where you will use, and how you will use, the Merkerva.

If we send it into a full battle on some plain in Europe or in the desert against a mobile enemy, it will show serious deficiencies. It is a tank that has been created for the very special needs of Israel. It needs to have infantry skintight, and to have a better chance of survival against unconventional weapons. Speed is not much of an issue when you are supposed to chase infantry around, nor when you are supposed to defend the border.

The Abrams was developed as a tank of maneuver. It was argued that the limited numbers of western tanks couldn't stand up to the hordes of Russian tanks in a normal battle. Thus the tank was supposed to shoot-and-scoot, staying away from major enemy formations while inflicting losses from afar. As we have seen, that has been rather successful, but then again the desert is the natural habitat for a tank like the Abrams, while the Russian tanks with their smaller size and in general better speed (though lesser stabilization) are perfect for the broken European terrain (a village here, a wood there, small river over there, little hill in front). In such terrain it would have a good chance of closing with the enemy, if he opted to stay in place. The endresult would be a matter of doctrine.

The Merkerva is more of a Tiger, while the Abrams is more of a T-34, though neither are great comparisons.