I find the BB DVD to be fine as it is; I don't think there's much, if any, need for improvement there.
For some reason I don't find the aspect ratio change of TDKR to be distracting on home video, but that may have something to do with the shape of my current TV. ( It is admittedly a little weird to have been a widescreen-only diehard for so long, only to end up watching a film that often fills the whole screen. )