What makes the GMLRS most useful is not just its accuracy, which is about the same as air force JDAM GPS guided smart bombs, but because the 200 pound GMLRS warhead produces a smaller bang than the smallest JDAM (500 pounds). When it comes to urban fighting, smaller is better. Less collateral damage, and your troops can be closer to the target when the explosion occurs. In Iraq, the 200 pound GMLRS warhead is just the right size for your average Iraqi house. The house, and the bad guys within, are destroyed, and adjacent structures suffer minimal, or no, damage. For that reason, even some Iraqi politicians have come out in praise of the GMLRS.
In order to get more GMLRS, all new MLRS production is being switched to GMLRS, and a retrofit kit, that will turn unguided MLRS rockets into GMLRS, has been introduced. The army believes that GMLRS will remain the most useful smart weapon, even with the introduction, later this year, of the hundred pound 155mm GPS guided Excalibur artillery shell, and the U.S. Air Force's 250 pound JDAM (the SDB, or small diameter bomb). Both of these weapons pack a smaller punch than the GMLRS, and that may be a drawback in some situations. Ground troops are certain that the GMLRS warhead is just right, at least in most cases. But the Excalibur and SDB will get a workout anyway, and they will probably prove useful.
The Excalibur is particularly looked forward to by ground troops because, like the GMLRS, the firing unit is controlled by the ground forces. Moreover, there are more artillery observers (who can call in artillery fire, from guns or rocket launchers), than those available for calling in air strikes. The artillery is always there, 24/7, no matter what the weather. While the troops like and respect JDAM, when they are getting shot at, they need fire support right away. Sometimes it takes a while for the air force to get a bomber overhead, or for an air controller to arrive. But artillery is almost always available sooner.
All future MLRS rockets will be "smart" (GPS guided), and older, unguided rockets, will be upgraded to "smart" status. This is because that, since large quantities of the new GPS guided 227mm MLRS rocket (officially the "GMLRS Unitary rocket") arrived in Iraq earlier this year, the troops realized that this was a near-perfect artillery weapon. There have been no reliability problems with the GMLRS, which has a range of 70 kilometers and, because of the GPS guidance, it has the same accuracy at any range. Unguided rockets become less accurate the farther they go.