eBay isn't a bad place, in general. That said, popular electronics, especially smartphones, are a place where scamming is likely the highest.
I wouldn't necessarily avoid eBay, but I would try and sell it locally anyway. After eBay fees, PayPal fees, and shipping fees, you are likely to make the same amount, or damn near it, locally.
Keep in mind, too, that you wont have access to your funds immediately, unless you are a somewhat frequent eBay seller. I don't know what that number is (I am sure it can be looked up), but if you sell things once in a while, eBay holds the funds for a set amount of time or until the buyer has left positive feedback.
As far as eBay siding with the buyer 100% of the time, that is untrue. I will say that if the buyer has hundreds or thousands of good ratings and you have something like three, and the buyer isn't prone to opening cases with eBay, you likely have a lesser chance.
I always video tape the act of packaging and dropping off higher value items. I have been told (on these forums) that eBay and paypal don;t take video evidence. All I can say is I used it once on an iPhone 3GS sale. I have no idea if it helped (the don't tell you why they ruled in your favor), but I uploaded the video to youtube and attached a private link, among the general information such as shipping date, tracking, receipt for the product, etc.
For a while I was a powerseller and actually sold quite a few ATT unlimited plans, used/new sims, etc. Never had an issue with any of that, which is funny, because I never added tracking to any of it (obviously not for an unlimited plan, and a sim I just dropped in an envelope with a stamp). People could have claimed they never got the data and there was nothing I could have done.