Not necessarily a strange question Podmog! I was Secretary for my PCC for two years and a member for four and found it interesting and generally worthwhile - there were some Vicar of Dibley-type scenarios, I have to say. But it does help you to get to know how your church makes its decisions - about worship, building maintenance, community outreach; in our case, it was also the process of choosing a new vicar. (And that was a real eye-opener).
There is also the element of influencing policy to further your own ends, in that at the time I was the only member with a small child, so could fly the flag against people who thought babies in church were a disgrace. They exist, unfortunately.
Rural Parish Council work, I think, is a lot more responsible and wide-ranging, more like local government. I guess you do mean PCC?
I'd say go for it. I made some interesting friends from people I only nodded to in church before I sat on Council with them, and it was nice to think I was contributing to parish life in some way.