I've been a Tivo user for many years. Started with Series 1, went to Series 2, and I'm thinking about moving to Tivo HD, but I have a few questions before I dive in. 1. How are the UI response times for the Tivo HD? This was my biggest complaint with Series 2. The software's become so bloated that there's a 1-3 second pause between every key press. The Series 1 was very snappy, and I'm hoping that the Series 3 systems are this way. Otherwise it's a deal breaker. 2. I currently have a Motorola HD DVR from Comcast. Yes, it's beyond awful, but is there anything (besides VOD) that the Tivo HD can't do that it can? 3. Besides HD and dual tuners, anything noticeably different between this system and the Series 2? Limitations? Thanks for any insight.