When I was a freelancer in Germany (i.e. up to last year) most "recruiters" were scum. I can't speak about the ones that focus on permanent positions but nearly all of the "Projektvermittler" (i.e. glorified temp agencies) were trying to guilt me into lowering my rates for them (because they'd charge the client 2-3x on top of that), tried to get me to sign NCAs far beyond the scope of the project (which is legally unenforceable but backed up with serious threats that would make anyone think twice) and were about as dishonest and intransparent about the entire process as humanly possible.

Oh, and of course they would keep bombarding me with Java/XML projects just because my CV (which they doctored and redacted before sending it to the client) mentioned that I had once worked on a Java project (but specialised in something entirely different since).

The one project I actually followed through on turned out to be a total disaster. Other than that, all my work had been directly for clients without a third party -- and that worked out far better.

If you're an inexperienced solo freelancer and want to work for big corporations, sure, recruiters are the way to go. Other than that, IMO you're nearly always better off skipping the middle man and taking the entrepreneurial risk (which is fairly manageable if you don't allow the client to build up several months worth of outstanding payments).