A Key does not have a particuliar taste or flavor; modes do.
Since the step pattern is the same for the major scale in all the keys:
Root + W+ W + H + W + W + W + H. The flavor remains the same.
However, there is difference in the pitch when you change Keys.

Modes provide a different flavor, becouse the step pattern is different.
Take for example a Lydian Mode, the step pattern is :
Root + W + W + W + H + W + W + H.
Compare this step pattern to the major scale and you will see that they are different. (The fourth degree)

The Lydian mode has a different flavor and is used a lot over Jazz progressions.