Yes, it certainly is worthwhile continuing to pay in this. It is a final salary scheme, what the media are too fond of calling agold plated scheme. I am a member of the Hampshire scheme. People in the private sector would kill to join something as good as this. Although government is trying to erode the benefits, remember that, in the current economic climate, if you are made redundant at age 55 (getting close), at 55 or over, you will be able to draw this pension immediately.
Do not even think of leaving. Finally, the scheme have a statutory duty to issue annual statements of your pension entitlements. Send an email (don't do it verbally) to HR, and demand that they sort this out.