I set up my chromecast this morning. watched a few hours of tv and didn't see any connection problems. very pleased so far.
Only 10/100 though 
You weren't expecting a USB3 bus in the device, were you? You could probably hook a gigabit adapter up to it, but as with the TS4K, it'll probably max out at 200–300Mbps anyway. A stable 100Mbps connection could still be superior to a wireless AC connection.