I just got an original (used) Transporter which is identical design save for the front knob and compared to my friends Touch. There was no comparison, the Transporter won hands down when used as Source & DAC, likely due to the improved power supply over the Touch.
You can also get a newer firmware which allows you to change between a sharp and slow roll off. Some say the slow roll off has a more natural sound at the expense of the top most "air". I haven't had enough time yet with the piece to A/B the two modes but I ran the Touch comparison in slow roll off mode.
I haven't had much comparison to any standalone DAC's but I'm curious to try mating it with a Burson DA-160.
You can also get a newer firmware which allows you to change between a sharp and slow roll off. Some say the slow roll off has a more natural sound at the expense of the top most "air". I haven't had enough time yet with the piece to A/B the two modes but I ran the Touch comparison in slow roll off mode.
I haven't had much comparison to any standalone DAC's but I'm curious to try mating it with a Burson DA-160.