This thread is far more useful
http://www.pprune.org/professional-p...2010-12-a.html
Half the people who I know who were employed in the last year by the company I now work for were 30-35, so I wouldn't say anything over 25 is a problem.
Over 40 I wouldn't bother starting, you will be slower to learn the new skills required, particularly at the pace expected from you on a type rating, and other life issues and responsibilities are going to make full time training harder.