If you are thinking about a new job, may I suggest that you research both the consultancies and consultants you work with thoroughly. There are a number of high quality organizations and boutiques which exist purely to help candidates find the kind of job satisfaction they couldn't achieve on their own.
However, these professionals are outnumbered by the KPI freaks who spew rubbish about "building relationships". (Good recruiters don't talk about doing this, they simply get on with it).
All below average recruiters simultaneously claim to be the number one suppliers to every investment bank. Apparently they are so skilled at "selling candidates in," they could place Gadaffi as the head of Amnesty International. They'll always ask to meet for a coffee because they don't have an office. They cold call you from their bedrooms.
Great recruiters can be partially identified by what they don't do, rather than what they do do. If a recruiter doesn't do any of the following, he (or she) may be great. I cannot wholly vouch for this, however.
Great recruiters don't: Exaggerate their earnings
Recruiters telling you they earn $160k+ per year should consider a career with the Treasury, where miscalculation is rife. Would you want to work with someone who believes you are so gullible?
Great recruiters don't: Fail to give detailed feedback on every occasion
If, after more than a month of waiting, all it amounts to is, "they chose someone with more experience," the reality is that they never sent them your resume in the first place. It was merely added to a database so that somebody's pointless targets were hit. If they do send your resumeb anywhere it will end up going to your manager.
Great recruiters don't: Surf social media sites
You should always ask a recruiter where they got your details from. A good recruiter will have acquired a referral from a colleague.
A bad recruiter will lie and say, "You were on our database." By this they mean social media sites. They have done no prior research and just called you up via the switchboard. Never work with recruiters who lack such respect for confidentiality that they'll call you at work. If they are passionate and good at what they do, they'll stay behind 'til 10 p.m. at night and call you. Believe me, I have done it.
But I am working for your satisfaction, not my own.