The other question you might want to know the answer to is do the DVDs suffer from the dreaded (for lack of a better term) NTSC Slowdown.
It's been more of a recent thing, with sets like Red Dwarf X and Doc Martin S6 being noticeably off because the audio wasn't pitch shifted to sound correct...
I'm not sure they were filming shows in High Def as far back as 2002.
I mean, Doctor Who started in 2005 and wasn't filmed in HD until 2010. They did start going 16:9 in the UK earlier than the US, though.