This is coming from someone who has never sold on Ebay and only infrequently purchased but I imagine it would be one of the better places to get a good price but also the most likely place to run into hassles/dodgy buyers.
You open yourself up to a much wider range of potential buyers, hence, the opportunity to get a higher price. However, this also means you are more likely to run into less scrupulous buyers
A place like a forum is going to be to a large degree self-policing especially when many of the members have frequented for years. Dodgy buyers/sellers will be stamped down on fairly/very quickly. In comparison Ebay is going to be the Wild West. There's millions and millions of people and they all can't be adequately policed. Plus, some of the stories I here it does not seem Ebay is too interested in looking after the sellers rights...