Hi Kim,
This is not just my experience, any musicians/composers I've worked with and spoken to will say the same thing.
Re 'recognition', there's a fine line between gaining experience and being exploited, just be careful that's all.
I agree it's rewarding, which is why I mentioned working on small projects instead like shorts/Indy game pitches etc for experience / portfolio.
Sometimes saying no is a great way to build confidence too.
re 'advertisements for unpaid work and helping each other out',
Once again I agree but with small projects that at least include expenses and/or a token financial gesture.
Dean.