There was a lot of resistance in the army to the concept of Stryker wheeled LAVs (Light Armored Vehicles.) The new vehicles were expensive, not much lighter or as nimble as the tracked vehicles they replaced and suffering from the usual problems new systems are prone to. The most recent flap is over the armor protection. The Strykers are supposed to have armor that can stop a Russian designed 14.5mm machine-gun bullet (which is about 14 percent more powerful than the U.S. 12.7mm M2). There have been problems, with some of the ceramic armor not being able to stop a 14.5mm bullet. What's interesting is that the U.S. Marine Corps LAVs, which are lighter than Stryker, don't have armor that will stop a 14.5mm round. Nor do the Marine AAVs (Armored Amphibious Vehicles). In Iraq, the marines did not report taking many additional casualties because of this shortcoming, and generally praised the performance of their LAVs. While it's comforting to the troops to know they are traveling in vehicles that will stop a 14.5mm bullet, such a vehicle will be larger, heavier and require more fuel and maintenance. The marines went the light route and appear to have succeeded. The Stryker will probably do all right in Iraq, and is in more danger from critics paper bullets than any armed foe's metal ones.