Going through the tape deck will add distortion and greatly reduce the signal-to-noise ratio. Whether you count that as an advantage or disadvantage depends on what you are trying to achieve.

If you like the sound it produces, that's an advantage.
If you don't the sound it produces, then that's a disadvantage.
If you can't tell the difference, then there is no reason you should be doing it.

If you were me, you wouldn't use the tape deck.