I know this is a little late, but on pages 15 and 16 of this thread, everyone claimed that the only reason the DV-410V existed was so that Pioneer had something new to show at the 2008 CES. After reading manuals and comparing firmwares, the gamma control has been improved. On the DV-400V, the gamma options were High, Medium, Low, and Off. On the DV-410V, the gamma options were from -3 to +3. Ever since the September 2007 release of the DV-800AV/LX50/58AV, the gamma control always went from -3 to +3. Believe it or not, DV-410V firmware will successfully install and operate on a DV-400V. You just have to remember to change YJB to YGB the first time you do so. After that, it will respond to YJB firmware files. I understand that the newer DV-420V firmware will load on it, but USB won't work until you go back to either DV-400V or DV-410V firmware. I just thought I'd let you know that the 410 is an upgrade from the 400.