I am a Glock fan. Have been ever since I had my first one. That said, there is a time and place for polymer. And certain components that take a lot of impact abuse are probably not the first place I would eschew the use of steel. The plastic guide rod is one component that can chip or break which can then cause a number of ejection of feed problems.

Lone Wolf Distributors has a complete drop in replacement for Gen4 Glocks starting at $29.95:
Special features include:

• Solid stainless steel guide rod
• Precision CNC machined to accept a removable Allen head tip, for easy spring changes.
• 17-7 stainless steel recoil spring.
• Spring weight calibrated to factory weights.
• 75% heavier compared to OEM part. (1.4oz vs .8 oz)
• Available as a highly polished version for only $10 more. High polish option provides a smoother, quieter operation.

Have any of you upgraded your guide rod?  If so, please drop a comment with your experience.  (If I had a Gen4 I would give it a try for $30–not that I have had a guide rod go out on me).