A bit underarmored for an MBT, but the range does make up for it. You can't really drive this like a Gauss Rommel or a Manticore, relyign on heavy armor to carry you into effective weapons range and through the fight. Fortunately, that LGR means you don't have to worry about range, and being one of the few MBTs to carry a sizeable LRM rack is also handy. You don't have sheer armor penetration, but you can generate a fair number of hit clusters and hope for motive hits. If you can slow them down, you can back off further and finish the fight with the Light Gauss. Also, indirect fire means that Merkavas can always support each other, even if a platoon gets split up during a battle. While I wouldn't advise getting into close range with another heavy tank, that Streak rack does make an excellent backup weapon for when someone does close, be they tank or battlesuit.
I plan to run them alongside HPPC Manticores, rolling a few hexes behind the smaller(but more powerful) tanks. Ideally, a couple Tufanas would also be handy to bring along, to spot for all of the battle tanks.