what i have found, in the financial services business, is the RIGHT agents really do a great job of finding the right opprotunity for you.
I was registered with about 10.....and only 4 of them are really trying and setting me up with jobs that are right for me. so i dropped the other 6, as they don't care about me or my career-just my sallary.
I do have to say, i applied directly to a few major financial houses. the tough bit, if an agent who you really like has an 'in' at the company you already sent your cv into, due to conflict of interest they can NOT talk to that company about you-as you are already in their database. that's tough, and it happened to me for a job i may have liked.
so really, maybe it's more agency specific....but really interview the agencies. they are working for you, they will profit off of you and you want to be sure they are representing you correctly!
i've gotten the most respect and the most results from being tough with them. letting them know i know the recruitment game.....and it's worked wonders.