Ive only had my touch for a week or so and havent connected an external drive (yet). Nevertheless, I am very impressed. Right out of the box, it bettered the dynamics of my Roku Soundbridge, and I love being able to select the stream (if more than one is offered) on internet radio.
I do feed the digital output directly to my Levinson 360s DAC . So far Im very happy despite the learning curve. (I never owned a Squeezebox before.) Well worth the $300 investment.
Sorry Ive never heard the Transporter.