1) Given the power profile, the 770 isn't slow for a 2005-2006 device. N800 isn't slow for a 2007 device.

2) Hardware-based motion video playback accelerators are limited in the codecs they can handle. Mplayer supports a wide variety of codecs.

3) Going from two SD slots to one SD slot would be an 'improvement' like switching from science to creationism in public schools.