So how much of an advantage does a CBIP, or someone with another certification, have over someone with real-world experience?
No certification should be a replacement for real-world experience. I can't speak to other certifications, but knowledge and skills testing is an essential component of becoming CBIP certified. You have to have real-world experience to pass the exams.
TechTarget provides enterprise IT professionals with the information they need to perform their jobs - from developing strategy, to making cost-effective IT purchase decisions and managing their organizations' IT projects - with its network of technology-specific Web sites, events and magazines.