The Apple TV have been tested wireless (using both 2.4Ghz and 5.8Ghz with 802.11n) and wired (using a power line adapter).
The difference in speed between wired, at 11mbps and wireless, at 30mbps, is substantial in my eyes. This was tested between a desktop wired to the router and the Apple TV. I have not tested the port where the Tablo is plugged in (using power line adapter) to the same desktop.
The Tablo itself was tested on wired, and both bands of wireless as well without any inprovements.
In all scenarios, with a channel that has strong signal, viewing on he iPad never lags, on the Apple TV it buffers.
Streaming of movies from my library on the desktop using the AppleTV is without issues. I could attempts to temporarily relocate the desktop to where the Tablo is if we believe the actual PLA or location of PLA is the issue. But why the discrepancy between the experience of the Apple TV and the iPad?