I agree entirely - the Stryker isn't meant to go up against tanks. But the original article indicated they were intended to get "there" quickly - meaning they're likely to be the only American unit in front of an advancing enemy. Unless the enemy obligingly plays by the "rules," he's likely to have tanks. Regardless of what the Stryker is meant to fight, in such a scenario what we will have is a vehicle that has less maneuverability, far less air transportability (= fewer men and vehicles deployed), less armament options, and a larger profile (bigger target). Not to mention the much greater vulnerability of that large set of wheels (compared to relatively short and mostly steel tracks) to various unpleasantness. And something tells me that, despite the much greater weight, its armor isn't any better than that of the M113A3.
But all of these shortcomings are apparently more than made up for by the fact that the Stryker costs much, much more than the M113A3. Further, since it has very little parts commonality with existing systems (the M113 series remains in the logistical system), there's the added bonus of the additional burden on the Army's entire logistical system.
My assessment of the armament options is based on the flexibility of the GE modular turret system mounted on the M113 and those variants we all know and love: the 4.2" mortar, the Improved TOW Vehicle, and the Vulcan. We must assume the enemy isn't totally moronic and has some degree of combined arms - light and mech infantry, tanks, artillery, AA, perhaps some type of combat engineers. Just a few high rate of fire AA guns and a mix of both shoulder-fired and ground/vehicle mounted missile systems, particularly IR systems and some good, old-fashioned Barrage Ballons (cheap, simple, invisible to radar, deadly to low-flying aircraft) and the only air assets we dare deploy in support of our Strykers are UAVs, F117s, and B-2s (only 21 B-2s in the inventory and something like 50-70 F117s). Some fairly rudimentary jamming systems may well prevent effective use of UAVs. This all adds up to very bad news to those guys in the Strykers.
Now, mind you, I'm not saying the situation is all skittles and beer for a force mounted in M113A3s. But since you can probably deploy 2-3 times as many M113A3s because they're actually C-130 transportable and I believe a C-17 can carry 2, you'll have a lot more forces ready to fight. Add in those neat combat support variants - most of which don't have to be upgraded to 'A3 variant to be effective - and you are much better prepared to do more than die in place. "Quantity has a quality all its own." But we're also talking more maneuverable, more survivable, and much cheaper.
An Israeli general once made the following comment about an entirely different topic, but I think it's most appropriate (wording isn't exact, 'cause it's from memory): "We are watching your experiments with great interest. But, unfortunately, in Israel we have to take war seriously." I'm not saying the Stryker is a pile of excrement. I simply maintain that it is far, far from the best choice. Newer isn't always better! But, like NASA refusing to use Space Shuttle External Tanks as part of the Space Station, the Army is blinded by New and Sexy and Congress by the copious quantities of Pork. I suspect the Stryker will do as well as any other brigade would when deployed to Iraq in the current situation (assuming the other brigade would have all the extra "toys" the Stryker brigade gets). But that ain't comparing apples and apples by saying one bridage is as good, or perhaps better, than another. In a rapid deployment situation, in the same time you managed to deploy a single brigade of Strykers, you could deploy 3 brigades of M113A3s - that's the combat units of an entire division! If you were the enemy, which would you rather face: A brigade of Strykers that don't have a lot of cross-country mobility or a division of M113A3s that can maneuver across virtually any terrain, including crossing water obstacles without any real advanced prep? The answer is obvious unless you've been consuming recreational pharmaceuticals.