Of course, there is no advantage to HDTV when watching SDTV programmes.
However, more and more HDTV programmes are being made in the US, and the BBC has probably started now (they have that 2010 pledge to make everything in HDTV don't they?). Star Trek: Enterprise series 4 is in fact recorded not just in HDTV, but with fully digital cameras. Which they then play about with to make it look like it was done with celluloid!
"Joey" is also shot in HDTV, and no doubt lots of other programmes that will be coming here soon.
And believe it or not, the US producers have finally realised that there is little wisdom in making 4:3 HDTV programmes, the two programmes above are in 16:9. So when Joey hits the shores you won't have to wonder why everyone in LA is so fat.
I enjoy watching the Good Life too, but that is more down to the delicious pertness of Felicity Kendall, as well as the fact that it reminds me of my native Surrey. It is available on DVD now. But I see what you mean about the colours, they are vibrant. I have a theory that realistic reproduction is not always best. Take music for example, people will spend £20K in order to get the flattest frequency response they can, but you know their lives would be a lot happier if they just added a little bit of bass to their music.