I think like anything there are good and bad eggs about.
I know someone who has very little prospect for employment but seems to be getting fantastic help from his JSA. His age counts against him, and he has phychological issues, but they keep offering to subsidise his training. He decided to do a course that needed Microsoft Office, and they bought it for him. He has now signed up for a different course, and when he gave the details to his JSA, they said they could've paid for it for him if he had given them the invoice, but they dont reimburse since he has already paid. (He will keep that in mind for further terms.)
So, he is having to be the one to go out there and find what training he wants, but they are quite happy to support him with the financial expense fo that training.
I've always been of the opinion they weren't really of any use finding a job, but good for funding training, providing a resume, and teaching interview techniques.
I remember when my XH was with a JSA years ago, they even paid for clothes suitable to go for an interview. Actually now that I think of it, at the time it was an odd situation. They told him that they had a certain amount of money to spend on him (it was quite high - something like $2500 over the course of six months) and offerred multiple suggestions of what to spend it on.