Jfrech, i don't think that you get less digital reflections with a longer length, you just have more line loss to "absorb" them on the return trip back to the transport. This is a two way street though, as a longer cable also has more loss making the initial trip from transport to dac too.
Having said that, one of the reps from Kimber specifically told me that they liked 1.5 meter lengths for some reason. Since different cable geometries and materials used alter the ELECTRICAL length of a cable, i have a hard time believing that any one physical length could be better than another. The fact that the nominal impedance of the cable does not change with length also makes this sound kind of fishy. I must admit that changing cable length does affect the loading characteristics of an RF transmitter though. The fact that the digital signal is RF based might lend some creedence to their statements.
Doing some studying of this subject is on my list of things to do. I'm working on setting up a test bench in a spare room to do my AC pc / filter / plc testing as i type this. The digital stuff is further down the road behind a few other projects though. Sean