Tried it with a few: an old FIIP E5 I have lying around, a cricri+ I had for some time and the really great sounding NECO V3(.1), this one is several steps above the others probably compared to your leckerton since this on standard also comes with op8610 just like Neco (Neco is one op amp per channel)
The difference in sound signature from line out to heaphone out is clearly noticed
Maybe this is related to how sony handles the s-master mx section, amplifying directly in the digital domain thus avoiding a dedicated dac circuit altogether. Not sure if the sony line out bypasses the digital domain amp, probably not since it´s circuit dependant but anyway line out on the sony´s does sound too much dry and thin (at least to my ears)
Bummer, well I will find out for myself tonight. Any other opinions of people using the WM-port line-out?