I have an ATV1 3.02 and aTV Flash (current version) and I am not happy at all with the web surfing capabilities.
1) SLOW - both apps are horribly slow and unresponsive.
2) Crashing - both apps very quickly lock up my ATV and I have to restart (one of the few things the RemoteHD does well)
3) Firefox window is larger than my TV screen (height), but there is no way to properly resize it. I've tried the restore window buttons, but they don't fix it.
Of course, because Apple is so pig-headed about not being able to use any edge of a window for resizing (one of the few things MS does correctly), I can't resize it manually.
I am not pleased.