First of all: I love channels on ATV - this is last missing puzzle on my ATV. And yes, I herewith confirm, that it is also working in Austria.
But, the issue I face sometimes is following: When either sometimes Channel crashes (which happens sometimes when scrolling through the guide) or when switching channels, the entire time-shift buffer is lost. This is somewhat of bothersome, as a click on a wrong button or crash will swipe your entire buffer. Last time it happened that we have time-shifted a channel to ff over the ad breaks and clicked a wrong button and everything has been lost.
Christian