Hi Pete,
I'm very happy with the audio from the LX73. I have to admit I need to upgrade my speakers - currently using some 14 year old Mission 734 floorstanders which cost £400 at the time. Nevertheless, the amp sounds great with CD, Blu Ray and iPod sources. The build quality seems great too. I'm feeding an LX54 BDP, Sky HD box and xBox360 through the LX73.
My only comment on the design is that I would prefer to have the iPod connections around the back so I could just leave the cable connected and sitting to one side.With the connections under the front pannel I have to disconnect the iPod cable each time I want to close the front pannel - not sure if I'm going to end up with a loose connection after some time (have never experienced a USB cable having a loose connection so maybe it will be ok).
The LX73 replaces an old Yamaha av receiver - about 12 yrs old - cant remember the model number and working away from home so unfortunately unable to check tonight.