The striders are just one of the many technological innovations that have come out of the wastelands. Sure, the world's great powers have sunk fantastic amounts of wealth into creating power armor, combat robots, soldiers who don't need armor, and mecha, but with a fraction of the cost, the wastelanders can field weapon systems of similar firepower.
The Strider is a relatively simple combat machine. The technology is based on the general utility leg suit, but replacing the lighter legs and chassis with heavier gear and adding armor and weaponry.
The Yeti: the Yeti was pioneered on the Neo-Soviet tundra, where Eurasian Alliance forces had the advantage of armor and power, but were hampered by the terrain and slow. The Yeti was built from the remnants of neo-Soviet infantry transports and war droids. The machine had a heavy armored chassis, stout legs, and an open cockpit, a common strider feature. Many of these early striders were destroyed before the terrorists who built them figured out the real way to use them. Once they learned to avoid stand up fights, the Yeti proved itself a versatile war machine, so long as it avoided the Alliance super heavy tanks and walkers. The most common Yeti configuration mounted a pair of infantry support machine guns across the front, and a gondola mounted heavy machine gun. The biggest flaws of the machine were it's open 'driver's seat' style cockpit, and the fact that only the most experienced operators could handle the manned gun and drive the machine at the same time.
The Spider Monkey: The Spider Monkey is a product of China and SE Asia. The strider was originally designed to work in forestry and agriculture, where it's multiple arms would be useful for carrying tools and manipulating heavy loads, but at a fraction of the cost of work over mechs. The Spider Monkey contract failed, as it was cited as being too dangerous to the operators, plus damaged units had a habit of catching fire. The machine saw limited production and was eventually stolen through a ShadowLaw shadowrun. The stolen strider was put into production, and instead of power tools, the secondary arms were equipped with bolt on assault rifles, and the primary arms were fixed with a variety of short range high damage weapons. Grenade launchers, rotary assault cannons, flamethrowers, and hydraulic claws and crushing arms. The machine started making runs as the Heavy in shadow wars and shadow ops, bringing the firepower of a heavy power armor suit without the hacking vulnerability.
The Shredder: the Shredder is a hybrid wheeled vehicle/strider. The main body houses a large gyroscopic stabilized wheel and electric drive system, but mounts on the sides, a pair of forward guns, and a set of prehensile 'arms' that it can use for balance purposes. Shredders were devised as fast transports in rough terrain, and would have been abandoned if not for their massive durability. A shredder can typically survive staggering falls undamaged, and is a popular tool among highly mobile wastelanders. The term was originally only applied to a certain type, but now, all uni-wheel machines are known as Shredders.
Stormcrow: The Stormcrow is an uncommon strider, large and broad, easily targeted. The machine demonstrates it's effectiveness by it's ability to carry dozens of rockets and guided missiles into a battlefield. The appearance of a stormcrow typically indicates an escalation in the intensity of combat as this strider carries enough firepower to decimate a power armor trooper squad and even poses a threat to lighter mecha, should it concentrate it's fire. It retains all the typical vulnerabilities of the strider, an open body design, primitive tech, and is entirely dependent on the skills of the driver. In engagements, the Stormcrow either ends the battle, or is the trigger that calls in bigger elements, typically actual combat mecha.
Mantis: The Mantis is light and it's fast. It doesn't have anywhere near the firepower of the other striders listed, but it compensates for this by being equipped with both target finding gear (basic laser designator) and communications equipment. Rather than being a basic scouting machine, the weaponry it carries is scalpel like in it's precision and is typically laser based.
Anvil: The Anvil is the attempt to produce a strider with mecha like endurance. Anvils are large and slow, with ample armor, and they have a decent amount of firepower. The main use of the strider is to serve as an anchor in a battle line, or as a walking target. Despite it's slow speed and poor combat performance, Anvils are popular striders, and most are bedecked with colorful ethnic decorations, skulls and the bodies of enemies, vivid animalistic colors, and so forth.
Rhino: almost without fail, experience Rhino pilots are deaf. The Rhino is the lower body of an Anvil, with the upper armor shell removed and replaced with a 75mm cannon. The gun is exposed and has an autoloader, the one mechanical concession to the pilot. The pilot aims the gun by pointing the chest of the strider at the target and firing. These striders are most commonly used to engage power armor units in close range combat, so that the gun has a chance to penetrate the armor. As such, Rhinos tend to be first round targets in close range combat.
Combat Usage: The Strider is technically a primitive unit, controlled with control sticks and steering wheels. Gunnery is handled with basic iron sights and the machines with arms have basic armature control systems. In combat, the machines are limited to the skill of the drivers. Likewise, they are HIGHLY vulnerable to anti-armor and anti-mecha weapons and tactics. Most of the third world, underworld, and terrorist factions who use these machines aren't expecting to get into toe to toe combat with uniform military forces. Striders typically fight other striders, cobbled together wastelander war buggies, and the armored fighters of the wasteland tribes.
There is one area where the machines do excel. When tech is taken out of the equation, such is in the instance of shroud generators, cyberwarfare ops, static bombs, or electronic white outs, the strider remains a viable platform. In this situation, the machines can fire up, go stomping into battle, big guns blazing, while the other guys panic because the computers and communications are down, and the targeting systems are dead.
On a final note, the Strider is a mecha-mook. A large mechanical stomper that is easily shot up, easily stolen, or easily used as a gun toting mule to bring more guns to shut down high end PCs with extensive cyberware, firepower, and abilities, without resorting to ratcheting up to deploying mecha.