Flavor notes or profile of truffles?
Uncooked?  I was shocked at how unimpressive the flavor of raw shaved truffle was.  It was kind of earthy, not particularly strong in flavor; in this case the truffle was probably not fresh enough.  When heated and allowed to release their full flavor and aroma into food though, they are phenomenal.  There's a rich, luscious taste and smell, with an almost petrol pungency to it. The latter is primarily from the 2,4-dithiapentane, which truffle oil replicates, although it has a harsher and less complex flavor.  Truffle oil will give you this top note, but without any of the additional layered complexity.

All this said, different people have different reactions, and freshness matters greatly for raw truffles.  If you really want to try truffle, canned or jarred truffle can be had in small quantities for under $20.  The flavor is quite distinctive, unique, and pairs well with cream, milk, cheese, and butter.