What I don't see anywhere is a list of reasons why I should go to the trouble of upgrading from my seemingly stable 1.3.8a to 1.3.9h. What I do see is a list of convoluted and time-consuming steps, which may or may not cause a lot of headaches and loss of customisations.

What compelling reasons are there to go to the effort of upgrading from 1.3.8a to 1.3.9h?

Cheers.