The Contemporary lobby is great. The Yacht Club is fine too, but I don't think it was a significant change.
Old Key West's lobby change was a disaster; it's atrocious compared to the old lobby. I'm sure not everyone feels that way, but the complaints about it seem pretty widespread compared to some other Disney changes.
Regardless, I'm not sure we're talking about the same thing. No one is suggesting the resorts stay exactly the same, but keeping the theme is important. Otherwise there's little reason to stay there compared to other, cheaper options (or similarly priced options that are much better).