Yeah Dawn of the Dead still has the great characters, music, excellent pacing, and a really good sense of scope and dread that makes it a great film. There a lot of thought out depth to the film that makes up for it's aged features. Can't really say the same for Day since it was too serious and mean spirited for its own good, but I still enjoy it. Land will age worse than any of those films though (actually it already looked outdated when I saw it in the theatre).
The only reason Romero's recent films are so terrible is that he has gotten old and doesn't have the heart to make them anymore. It's very much like how Carpenter went down (though he did redeem himself with his fun Masters of Horror episodes). The only way Romero seems to be able to make films now is if he slaps his name in front of a zombie flick. He's pretty much become his own creation. A zombie making movies. :'(