I bought a NAD 515 back in February, but am in the process of selling it, having replaced it with a Cambridge 651. I would describe the overall sound of the NAD as smooth and 'analogue'. This was fine on brightly-mastered CDs - in fact the 515 really brought out the best in these discs, with its natural and 'musical' delivery. However, any disc that wasn't naturally as bright sounded a touch flat and dull. The NAD also had a tendency to sound compressed and a bit mushy when the music got louder and the soundstage filled up. I ended up going for the naturally brighter, more detailed Cambridge. I still feel this was a bit of a shame, because I loved the warmth of the NAD sound -- it just ended up being too smooth for me. Bear in mind the 515 was the entry model, so the 545 would probably have more detail and a better sound.