While I'm not familiar with The Plum Tree, the mention of PK Chang's and Cold Stone Creamery brings on a rant.
Don't you just hate it when some mom-and-pop operation, that's been doing fine for years, suddenly faces competition from a big national or multi-national chain and is put out of business? It's the individual entrepreneurs that make a city great, not the ubiquitous chain stores. I try to avoid the latter as much as possible. Today, in fact, I shook the hand of a new bookseller in the neighborhood.
He's across the street from Columbia's Barnes & Noble (am I right that Barnes & Noble started out as NYU's bookstore?) and the book suppliers sell to Barnes & Noble at a much lower price than they do to independants like him. Of course, that's because Barnes & Noble racks up a high-volume amount of, er, volumes, but often it seems the system is rigged against the little guy.