"but only because a) he was really hungry at the time b) he really went out of his way to build up a lot of contacts with a lot of top-notch talent."
And that was really the essence of what I was going to say. I think after a while anyone who is busy and being paid in the manner that a recruiter (or real estate salesman) is is going to go for the easy route and the low hanging fruit. Especially as they get busier. Because back and forth is time consuming.
It's kind of like a satisficing model. You need to keep the client happy enough to keep sending you projects and no more than that. 
Consequently in theory a new and hungry recruiter is really the one that will give you the best results but that assumes they have a file full of candidates and that kind of contradicts being new.
 There is truth to that book that stated that real estate salespeople get more when they sell their own house than your house. 3% of $10,000 is not $10,000 and it pays to move on to the next deal in your book.
I've never seen a industry that needs a fresh, iron clad
Application, but it has to be top notch. A hungry, smart developer could revolutionize the Realeste market
with the right code, and eliminate Realtors to a history
wiki. Plus--I would never need to look at their stupid
smiling faces everywhere. And yes, I know a house is the
biggest thing you will ever own--you need hand holding?
That's all your full commission will get. Smart Realtors
always cover their asses legally if you buy a Lemmon. This
is just my rant on Realtor's--especially full commission
brokers. The above post reminded me of how arcane buying
a house is.
The large bodyshops, OTOH, seem like a colossal waste of time to me. I don't trust them, and the candidates they offer have been almost uniformly disappointing.
His "secret" is that process, which also allows him higher than average access to passive job seekers. Let's face it, many (not all, but many) of the "best" candidates already have a sweet gig and aren't pounding the pavement looking and mindlessly applying to every job posting. This recruiter calls them and they take the call, because he's not just matching asses and seats like it was a musical chairs problem.
Candidates like him (he placed me once 17 years ago) because he's not perceived to be a time-waster, and hiring managers like him because I get better candidates through him (albeit at a lower volume and I "can't afford" him for every role).
That's responsive to your first sentence; to your second sentence, I generally agree. I have the luxury of having a strong in-house recruiting team, who are willing to selectively and smartly use outside agencies when it makes sense. As a result, I get to direct the flow of nonsense from outside agencies at my in-house team. ;)
I treat recruiters like widening the funnel, and haven't found any correlation that suggests they produce better results.
I have found the best results is hitting people up through linkedin.