LOL, I'm not alone in my thoughts
I think the 1st Relams boxed set is superb, as a note, it's artisitic style is very important in it's
feel...that sepia tone look and borders is truly beautiful.
Feel/soul is enormously imporant.
For example, check the early Thieves World books, mmmm, flavour of a fantastic stew!
Same with Leiber's Newhon, Tolkein's Third Age, John Norman's
early "Gor" books (before they became S&M weirdness, lol) etc.
The "feel" is far, far more important than the "crunch". The latter has to flow from the former, not the other way around!
Original Dark Sun, omg, that's fantastic!! Some unecessary crunch though (templars are just clerics, tough! deal with it, their bureacratic powers are nothing to do with their combat power as an individual), but the "feel" is delicious.
Spelljammer and Planescape were fantastic for flipping your mind with new ideas/settings.
I'm sorry, the 4th ed setting stuff so far, has been ABYSMAL, as far as I'm cocnerned, totally bland, boring, off-the-shelf
blahsville 
Note though, I love 4th ed game itself.
it's very annoying as the adventures have been great.
Also, there's no need ot destroy a setting to fit new mechanics in.
For the Realms it's easy, just say dragonborn have began appearing from ...some logicak place and tieflings have been around for some time anyway, just make them *rare*.
And well, that's about it, really.
Fluff != Crunch.
I also agree that detailing a setting too much ruins it, for some. I love the Realms in the 1st boxed set..
bam! huge area, lightly detailed, full of mystery,
woot!
Some add ons were great: City System for Waterdeep (damn those maps and tables were an almost sexual delight for a DM, lol), and Undermountain..hey, one of the best settings of all time.
But then...novels, some of which were dire, kind of got in way...Drizzt is a great character, but to me, Drow on the surface are rare as heck as most folk kill 'em on sight.
Drow are 90%
thoroughly evil shmucks, 9.999% "CN" self-preservation artists.
and the Time of Torubles,
barf! only the FR comic did that any good, if any of you have read it, bat that it was an excuse to have a very poor series of modules, have a complete non-believable no-user osme how usurp three gods, yeah, right!!!
Then with everything being detailed you feel little room for manouver.
Over all, as a DM, it just felt like I was being forced to accept all the things :/
the 4th ed changes to the Realms are even worse than the mess TSR made of Dark Sun (killing half the sorceror kings etc to fit a
novel seriesplotline, grrr, and the official history sucked!).
Ah well.
I'll stick with the original FR, Spelljammer, Dark Sun and Undermountain sets, thank you very much
And note, I'd be VERY happy to buy more Spelljammer, Dark Sun, Planescape stuff, if they do it well.