If you need the recruiter in order to get the interview in the first place, it doesn't matter how well you shine in the interview.
I once had a recruiter (he had my resume) contact me for a Novell admin position. And there was nothing related to Novell on my resume. Then I knew not to waste time with 'recruiters'.
The experience I've had with outside recruiters in the past 10 years is atrocious, though. All they're looking for is warm bodies to toss at a company, and hope one of them sticks. No or limited experience--they still want to present you...after modifying the resume you've sent them in Word.
Today's outside recruiters are inexperienced in and ignorant of the field ("Your last job was a fitness trainer??"), and borderline unethical.
I'm still surprised so many of them are in business.