I have also noticed that the 3D "sweet spot" it fairly small, but still large enough not to be an issue. If I stand up then the 3D picture gets bad ghosting, but as long as I'm sitting down it looks great. It definitely helps to have a TV mount for the wall that tilts so you can angle it just right.
As for the OS I haven't had any issues. We use Netflix and 3DGO almost exclusively and they both work quickly and the picture quality on both is great.