Look at that 4 ch. on your ebay item: the horizontal stab / elevator is installed backward in the picture. I wouldn't trust it at all from folks like that.
My advice: stick with a known name product, from a source you have some recourse with. I personally don't do foamies, I bought a Stryker B model, I am not impressed with it. It does do what the box says it does. Nothing more. I will stick to my glow arfs and kit builts.