An experience on the question of whether balanced connection can make a difference with shorter cable runs: Between my balanced DAC and balanced preamp, I experimented by trying 1m runs of two different cable types in both balanced XLR and single-ended RCA configurations for each type, and for both types, the balanced XLR examples proved superior (with volume levels compensated to match - the preamp allows for input-level offsets to be pre-programmed to within .1dB for accurate comparisions, which I remotely switched from the listening chair). In particular, running the balanced connection resulted in a presentation that was more dimensionally 'embodied', with fuller tonal saturation and dynamic contrast. These differences were slight but consistent, and musically worthwhile; the effect in balanced mode was unmistakably a bit more believable and engaging overall. So I can confidently say that short run length by itself ought not dissuade anyone from trying out balanced connection, especially with true-balanced components, but as Albert and others have noted above, everything is dependent, and YMMV. You just have to do the audition for yourself...
