From what I can gather doing research on composite vs. steel guide rods in CZ's, there's no significant difference in reliability or function...with steel being less desirable on alloy-framed pistols because of the marking/galling it would impart from recoil force. I think some feel that the flexibility of composite rods help give some leeway from leaving marks during impact/recoil in certain instances. Some feel that a steel guide rod helps add some muzzle weight to counter recoil/muzzle lift, others say it's not noticeable especially in a steel-framed pistol. I guess a composite rod would absorb some of that force better than the steel rod at that rear point of impact, but it is still a hard plastic compared to a rubber.
When it really comes down to it, I think our pistols will be fine either way. They are built very strong, and as long as we maintain them well enough and don't feed them a constant diet of real high-pressure stuff they'll hold up even without buffers. If I were shooting more +P or hotter defensive stuff out of my Shadow 2, I'd probably step up to at least a 15-lb spring....maybe more since the slide is lightened compared to, say, an SP-01. But for competition, I keep it mainly to 124- or 147-grain stuff that's pretty moderate. Definitely softer to shoot than regular range stuff like White Box or Blazer brass, or defensive ammo. If for some reason I ran short on 'target' ammo and had to scrounge/buy some hotter stuff, I think the gun would hold up fine for a few runs, even though it may be printing a little differently.
