I am generally an original aspect ratio kind of guy. But things like 'open matte' where you add extra information for the 'full frame' release didn't bug me. I'd rather have that on a 4:3 screen than black bars, but since 4:3 is now obsolete, it's kind of a moot point.
Didn't the Buffy DVDs end up being widescreen in Europe or something along similar lines? That is, they didn't crop the 4:3, but just opened up what was actually filmed to create the widescreen version? If I recall Joss Whedon wasn't thrilled with that... but frankly I'd probably prefer that version even with the occasional production equipment showing up on camera. I could understand why you wouldn't.
Cropping something from one aspect ratio to fit another is a no-no in my book. As are the various ghastly stretching modes for filling out widescreen TVs with 4:3 content.