I got the chance to test both. The W1000 I could not bare - I honestly thought something was wrong with them - thin, tinny, sibilant ad infinitum. I then tried the W5000. I bought it. Nuf said?
And whoever says you HAVE to have a $1300 amp is wrong IMO. I tried it with three amps now - X-Can V3 (good, a little bright with silver interconnects but great with darker copper ICs); a PS Audio GCHA (fantasticly clear, neutral, detailed) and a humble ASL HB1.
The latter is a $250 hybrid tube amp and it is one of the sweetest, most musical combinations I have ever heard. Yes, the W5000 can take expensive amplification in that it scales well; but at the same time it does not need it to mandatorily to perform magically.