I'm looking at a Series3 to replace my Scientic Atlanta HD-DVR box (Explorer 8300HD) from Time Warner Cable. However, I've been reading in some reviews for this unit (and the new Tivo HD) that the responsiveness of the menus are pretty sluggish. Is this still true for the Series3 with the latest software updates? To give you an idea of my tolerance for this, I found the Scientific Atlanta box to be a little sluggish but acceptable. I found DirecTV (can't remember what box exactly) to be too sluggish. I found the Motorola HD-DVR (again don't remember model number) to be way too sluggish. I really value responsiveness and speed in the UI. Nothing's matched my old ReplayTV in this regard. Will I be disappointed with the Series3?