Postwork isn't a must at all. If you're good at it, you can achieve some great details and lighting. On the other hand, if you know Poser well and know how to set up lights well, you can achieve great results without the need to postwork.

There seem to be a good number of people who don't really know how to use Poser, but are great at doing postwork, they achieve the same as someone who is very good at using Poser, but isn;t good at doing postwork at all.

I don't always do postwork, often I don't. But at times there are effects Poser cannot achieve or there are some minor errors and then I do postwork. When I'm working with specific lights, like candles, I do find postworking those lights very beneficial. It adds light effects much better then Poser does.

Artwork and 3DToons items, create the perfect place for you toon and other figures!

http://www.renderosity.com/mod/bcs/index.php?vendor=23722

Due to the childish TOS changes, I'm not allowed to link to my other products outside of Rendo anymore :(

Food for thought.....
https://www.youtube.com/watch?v=pYZw0dfLmLk