Here's a posting (edited for clarity) from another board that may offer some good insight on this topic:
"The Hindus have a metaphor: If you want to dig a well, you don't dig a hundred shallow holes. You dig one deep one, assuming you want water.
... in the beginning, everyone sniffs the wind. I too went through an ecumenical phase I look back on with understanding, but some embarrassment. It is in the Vedas, I believe, that the line appears, "Truth is one, wise men call it by many names." This is a very consoling line. It allows for sniffing the wind and not feeling that it's a waste of time. It also mitigates the rightful skepticism about a narrow-minded, rock-solid, and sometimes pig-headed approach to things.
"Truth is one, wise men call it by many names." Yes, it's quite consoling. But for anyone who is serious about their hopes and longings in spiritual endeavor, there's another shoe to drop. "Truth is one, wise men call it by many names" may be a true observation, but the other shoe is this: "Now prove it!" Intellectual and emotional appreciations of "truth is one, wise men call it by many names" or "smorgasbord spirituality" only reaches so far. Truth be told, it simply cannot bring peace to the heart. To the lips, perhaps, but not the heart. Somehow each individuals have to address that other shoe: Prove it!
And it is at this juncture that some students make a personal choice -- whatever the choice -- and start digging one deep hole. That choice will be pockmarked with failure and success ... but the student keeps digging ... and digging ... and digging. Fall down seven times, get up eight, as the Japanese say. Make a mistake, correct it. Make another mistake, correct it too ... over and over again.
This effort is not "better" or "worse" than some other chosen path. It runs numerous risks. But its advantage lies in the fact that there is honest water to be found and is worth finding. The object is not to prove something to someone else. The object is for the student -- for possibly the first time in his or her life -- to prove something to him- or herself..."
What exactly is Tolle offering that the Buddha does not?