From my personal experience I like to use here to sell as I have never had any issue at all with any buyer. They're polite, understanding & I like knowing any parts/bikes have gone to a good home.
I use Ebay as a last resort - Yes things tend to sell faster as it has a wider audience but the fees are ridiculous as are the time wasters. Selling on Ebay is often more trouble than its worth.
Never sold anything on FB but you're not covered & I've heard a lot of bad stories about scammers, people being held at knifepoint and such