Chris, I wouldn't worry too much about it being behind the TV then - I've done a few deployments with Aruba's equivalent of these APs, and in such a small space to cover, the TV is not a significant factor (most TVs have an aluminum backplate to the display element, which will tend to reflect the signal rather than attenuate it.).
The key difference between the Aruba and the Ruckus (from an antenna propagation standpoint) is that the plastic mounting option behind the Aruba tends to provide more coverage behind the AP, whereas the metal plate on the Ruckus will make it more directional... although there's still a big heat sink on the Aruba, and any commercial setting will be mounting to metal boxes, so the difference is probably less pronounced.