Yes I've basically heard Grace and a live DVD that I'm not sure the name of.
And I said that his version of "Hallelujah" was brilliant.
I don't feel the need to seek out the other titles you listed because I feel as though if I didn't enjoy Grace (which has been praised enough by diehard fans like yourself), then he's just not really my cup of tea. I feel as though after listening to what's agreed upon as his best album (though it was the only major label one he released really) and seeing a live DVD, I can say that I'm not a big Buckley fan. He didn't breach that "I want to hear more" threshold.
I usually don't enjoy his voice much (though I like it on "Hallelujah"), I don't like his songs (especially the lyrics), and I don't enjoy the production on Grace at all.
Can't you say the same about, say, New Kids on the Block? If I told you (which of course I'm not), "yeah they're old stuff sucked, but you gotta hear them on this live album -- it's a lot better," would you check it out? Of course I'm not placing Buckley in the league of NKOTB, but I'm just illustrating the point that you usually know when something is "your kind of thing" or not. Though bands do change sometimes, they USUALLY maintain a basic core of their sound. I'd be willing to bet that you feel perfectly fine about not giving NKOTB any more chances to impress you.